Home
Search results “Transaction signature bitcoin”
Bitcoin - Digital Signatures
 
09:48
A high-level explanation of digital signature schemes, which are a fundamental building block in many cryptographic protocols. More free lessons at: http://www.khanacademy.org/video?v=Aq3a-_O2NcI Video by Zulfikar Ramzan. Zulfikar Ramzan is a world-leading expert in computer security and cryptography and is currently the Chief Scientist at Sourcefire. He received his Ph.D. in computer science from MIT.
Views: 137679 Khan Academy
how to sign a bitcoin message - bitcoin signature
 
08:27
https://steemit.com/bitcoin/@bitsignal/how-to-sign-a-bitcoin-message-using-your-private-key I used the following github tool to sign the message: https://github.com/ReinProject/bitcoin-signature-tool
Views: 11460 blocksize
Digital Signatures and Signing transactions explained
 
08:04
You need to have an understanding of Encryption for this video to make sense 13uJjYF12aRVdwaiTmALx5XDfguQ9MnYtK
Views: 1809 Keifer Kif
Blockchain/Bitcoin for beginners 3: public/private keys, signatures... and first ever transaction
 
36:25
Detailed overview of public/private key encryption and live demo of exactly how digital signatures work on Mac, combining public and private keys and hash functions. Welcome to episode 3 of my series on Blockchain/Bitcoin. I'm joined once again by my girlfriend Nadisha who is my classroom pupil... I build on the hash function concepts from the previous episode and explain the basic concepts public and private keys and how to use them to create digital signatures - a key part of the bitcoin infrastructure. We demonstrate in a Mac terminal how you can generate your own keys and encrypt and decrypt and sign your own resources - learning by doing always works. We touch on bitcoin addresses, what they represent and how they are created. Finally I go back for a refresh of the bitcoin blockchain browser and look at the first ever bitcoin transaction in the "Genesis Block" to show what a real bitcoin address looks like. Bitcoin Blockchain browser https://blockchain.info Online hash calculator - great way to practice and familiarise with hash functions - one of the most important building blocks of Blockchain/Bitcoin http://www.fileformat.info/tool/hash.htm Course to date (previous videos) 1. Blockchain introduction https://youtu.be/xwA2TkcAQgQ 2. Hashing, blockchain networks and look at blockchain browser https://youtu.be/oxwMnqFNq9M SAMPLE COMMANDS: You will need to use your own document - pick any document, obviously your hash values will be different to mine. Also I had to use (right arrow) - since comments do not allow "chevron" symbols # EXAMPLE 1: # generate public and private keys openssl genrsa -out mykey 2048; cp mykey privatekey; openssl rsa -in mykey -pubout -out publickey; rm mike #encrypt with public key echo “the cat sat on the mat” | openssl rsautl -encrypt -pubin -inkey publicly (right arrow) cipher.txt # show the garbage cat cipher.txt # decrypt with private key - The cat sat on the mat cat cipher.txt | openssl rsautl -decrypt -inkey privately # EXAMPLE 2: Sign Alice in wonderland #check the SHA256 hash of the document to send - d9db7b8984d808b2821070cc6cc76e4415229d3356452b2a0f06ec3608f13b6c shasum -a 256 alice-in-wonderland.txt | cut -d" " -f1 # create a text file called signature which hashes the document and encrypts with private key shasum -a 256 alice-in-wonderland.txt | cut -d" " -f1 | openssl rsautl -inkey privatekey -sign (right arrow) signature # wrap the signature up with the public key, the document and the signature and send it … we just copy to another folder tar -cvf alice.tar signature alice-in-wonderland.txt publickey;mkdir -p inbox;cp alice.tar inbox;cd inbox;tar -xvf alice.tar # inspect the public key and verify with the sender that it belongs to the sender cat publickey #decrypt the signature with the received public key - d9db7b8984d808b2821070cc6cc76e4415229d3356452b2a0f06ec3608f13b6c openssl rsautl -inkey publickey -pubin -in signature # hash the received document - d9db7b8984d808b2821070cc6cc76e4415229d3356452b2a0f06ec3608f13b6c shasum -a 256 alice-in-wonderland.txt | cut -d" " -f1 # if they are both the same then the document cannot have been changed since it was signed by the genuine owner of the # private key corresponding to the public key
Views: 18132 Matt Thomas
Blockchain tutorial 6: Digital signature
 
04:48
This is part 6 of the Blockchain tutorial explaining what a digital signature is. In this video series different topics will be explained which will help you to understand blockchain. Bitcoin released as open source software in 2009 is a cryptocurrency invented by Satoshi Nakamoto (unidentified person or group of persons). After the introduction of Bitcoin many Bitcoin alternatives were created. These alternate cryptocurrencies are called Altcoins (Litecoin, Dodgecoin etc). Bitcoin's underlying technology is called Blockchain. The Blockchain is a distributed decentralized incorruptible database (ledger) that records blocks of digital information. Each block contains a timestamp and a link to a previous block. Soon people realises that there many other use cases where the Blockchain technology can be applied and not just as a cryptocurrency application. New Blockchain platforms were created based on the Blockchain technology, one of which is called Ethereum. Ethereum focuses on running programming code, called smart contracts, on any decentralized application. Using the new Blockchain platforms, Blockchain technology can be used in supply chain management, healthcare, real estate, identity management, voting, internet of things, etcetera, just to name a few. Today there is a growing interest in Blockchain not only in the financial sector but also in other sectors. Explaining how Blockchain works is not easy and for many the Blockchain technology remains an elusive concept. This video series tries to explain Blockchain to a large audience but from the bottom up. Keywords often used in Blockchain conversation will be explained. Each Blockchain video is short and to the point. It is recommended to watch each video sequentially as I may refer to certain Blockchain topics explained earlier. Check out all my other Blockchain tutorial videos https://goo.gl/aMTFHU Subscribe to my YouTube channel https://goo.gl/61NFzK The presentation used in this video tutorial can be found at: http://www.mobilefish.com/developer/blockchain/blockchain_quickguide_tutorial.html #mobilefish #blockchain #bitcoin #cryptocurrency #ethereum
Views: 12994 Mobilefish.com
How to do a Multisignature Bitcoin Transaction
 
07:49
How to use public and private keys to create a multi-signature address and then spend bitcoin from that address.
Views: 8619 Alex Millar
Advanced Bitcoin Scripting -- Part 1: Transactions & Multisig
 
59:58
This is the first part of a more technical talk where Andreas explores Bitcoin script, with examples from the 2nd edition of Mastering Bitcoin, focusing on the use of conditional statements, flow control, guard clauses and time locks. The examples will include advanced multi-signature scripts, hash time lock contracts and asymmetric revocable commitments. Then he answers questions about Bitcoin's quirky bugs, where Bitcoin differs from Ethereum at a scripting level, how SegWit works, how consensus rules change, and whether Bitcoin is more than just a currency. Watch Part 2 here: https://youtu.be/pQbeBduVQ4I This talk took place at the San Francisco Bitcoin Developer (@SFBitcoinDev) meetup on April 3rd, 2017: https://www.meetup.com/SF-Bitcoin-Devs/events/238773843/ Review materials on the topics presented: Chpt. 7: https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch07.asciidoc Chpt. 12: https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch12.asciidoc The fundamentals of Bitcoin script 2:17 Bitcoin's operators 5:00 Creating transactions (P2PKH - Pay to Public Key Hash) 6:30 Public Key CheckSigs, security by obfuscating public keys 7:42 Redeeming the script 9:05 The RIPEMD160 hash operation 12:05 OP_EQUALVERIFY, OP_CHECKSIG, & the elliptic curve digital signature algorithm (ECDSA) 14:05 Summary 18:30 Illustrating scripts: Equal, EqualVerify, CheckSig, CheckVerify, CheckMultisig, CheckLockTimeVerify 19:45 Guard clauses 23:02 Script-based timelocks 24:53 Flow control statements, interactive artificial intelligence 26:50 If, Else, EndIf 28:35 Unlocking scripts, what conditional flows do in Bitcoin 33:55 1-of-2 multi-signature script 35:44 1-of-2 multi-signature script with guard clause 38:28 2-of-3 multi-signature script 41:30 2-of-3 multi-signature script with timelock guard clause 43:20 BIP-113, how time is referenced in Bitcoin 44:42 Backup clause & other nuances in multi-signature schemes 46:58 Game theory, complexity from simplicity 52:36 2-of-3 multi-signature script, unlocking 53:45 RELATED: Bitcoin: Where the Laws of Mathematics Prevail - https://youtu.be/HaJ1hvon0E0 The rules of Bitcoin (part 1) - https://youtu.be/VnQu4uylfOs The rules of Bitcoin (part 2) - https://youtu.be/vtIp0GP4w1E Forkology: A Study of Forks for Newbies - https://youtu.be/rpeceXY1QBM Irreversibility and consumer protection - https://youtu.be/R107YWu5XzU Andreas M. Antonopoulos is a technologist and serial entrepreneur who has become one of the most well-known and well-respected figures in bitcoin. Follow on Twitter: @aantonop https://twitter.com/aantonop Website: https://antonopoulos.com/ He is the author of two books: “Mastering Bitcoin,” published by O’Reilly Media and considered the best technical guide to bitcoin; “The Internet of Money,” a book about why bitcoin matters. THE INTERNET OF MONEY, v1: https://www.amazon.co.uk/Internet-Money-collection-Andreas-Antonopoulos/dp/1537000454/ref=asap_bc?ie=UTF8 MASTERING BITCOIN: https://www.amazon.co.uk/Mastering-Bitcoin-Unlocking-Digital-Cryptocurrencies/dp/1449374042 [NEW] MASTERING BITCOIN, 2nd Edition: https://www.amazon.com/Mastering-Bitcoin-Programming-Open-Blockchain/dp/1491954388 Subscribe to the channel to learn more about Bitcoin & open blockchains! If you want early-access to talks and a chance to participate in a monthly LIVE Q&A with Andreas, become a patron: https://www.patreon.com/aantonop Music: "Unbounded" by Orfan (https://www.facebook.com/Orfan/) Outro Graphics: Phneep (http://www.phneep.com/) Outro Art: Rock Barcellos (http://www.rockincomics.com.br/)
Views: 27994 aantonop
Getting the ECDSA Z Value from a Bitcoin Single Input Transaction
 
06:43
In this video I demonstrate getting the ECDSA Z value from a bitcoin transaction with only one input. I also show the R and S values. The ECDSA R, S and Z values are used throughout the many layers of bitcoin to validate a transaction, The Z value is also sometimes referred to as the signed message. Transactions that don't contain valid inputs can be safely ignored, and the Z value is one of the properties that is used to check validity. This video shows me dissecting a very basic transaction with only 1 input and 1 output. The urls I show in this video are https://2coin.org/index.html?txid=bf474b96908ba7769120b2e8f2bfcbd2deca80c99b576b4b63bf18fb69e3d242 https://en.bitcoin.it/wiki/Protocol_documentation#tx https://2coin.org/doublesha256.html
Views: 2867 seanwasere ytbe
Bitcoin - Transaction block chains
 
11:25
The mechanics of a bitcoin transaction block chain, which is a construct that is generated by bitcoin miners and functions as a global ledger for recording and validating bitcoins. More free lessons at: http://www.khanacademy.org/video?v=QzDO44oZWtE Video by Zulfikar Ramzan. Zulfikar Ramzan is a world-leading expert in computer security and cryptography and is currently the Chief Scientist at Sourcefire. He received his Ph.D. in computer science from MIT.
Views: 206728 Khan Academy
Bitcoin - The security of transaction block chains
 
15:16
A detailed explanation of what makes bitcoin transaction block chains secure. More free lessons at: http://www.khanacademy.org/video?v=8zgvzmKZ5vo Video by Zulfikar Ramzan. Zulfikar Ramzan is a world-leading expert in computer security and cryptography and is currently the Chief Scientist at Sourcefire. He received his Ph.D. in computer science from MIT
Views: 80166 Khan Academy
Bitcoin Transaction Details - Part 1
 
15:47
A look at how a transaction is constructed This video is part of a larger online course, "From Barter to Bitcoin: Society, Technology and the Future of Money" run by Prof. Bill Maurer and Prof. Donald J. Patterson In addition to the video on YouTube there is a variety of other content available to students enrolled in the class. "In 2008, a person calling himself or herself or themselves Satoshi Nakamoto released a paper suggesting a system for an anonymous, peer-to-peer alternative money. Bitcoin was born. Although not the first digital currency ever proposed, nor the first challenger to fiat money, bitcoin is the first to have captured the broad imagination of speculators, coders, regulators, criminals and the mass media. This course puts Bitcoin in context: how do we understand money as a social, political and technological phenomenon? From discussions of ancient transactions to the rise of state-issued currencies, we will explore the social and technical aspects of bitcoin, its predecessors and potential successors, and how its features echo aspects of many different historical transaction systems. No prior knowledge of economics or computing is required. There is little academic writing on bitcoin. And this may be the first truly academic class on the topic. We want to put bitcoin in a wider perspective, to reflect on what it means for society, politics and economics, as well as how it helps us think about money both a social and a technical phenomenon. This class is not an advanced seminar on bitcoin--we will not be delving deeply into the inner workings of the system, but instead providing a bird's-eye overview with enough technical detail for you to be able to put media stories, hype and hope around bitcoin in perspective. Similarly, this is not a class in monetary economics--we won't go too deeply into monetary theory or policy, the money supply, or inflation. Instead the class invites you to think more deeply about one of the oldest systems of technology on the planet, and most ubiquitous: money, whether coin, cash, credit card or cryptocurrency, we humans have been making money for most of the past 10,000 years. How we do so in the future is a question bitcoin just maybe helps us answer."
Views: 31504 djp3
Bitcoin from the Command Line - Sending Bitcoin Transactions Programmatically with Javascript
 
17:07
One of the common complaints with Bitcoin is that it’s pretty hard to get started, and there’s a lot of overhead to making accounts and sending transactions. So I want to show everyone a really simple workflow that I’ve been using to interact with the Bitcoin blockchain from my command line using Javascript. This isn’t a workflow that I would recommend for long-term storage (though there isn’t anything wrong with it necessarily, I still would recommend hardware wallets for long-term crypto-asset storage) but it is a good workflow for hacking around, sending money and building apps. Video Notes: https://gist.github.com/AlwaysBCoding/4af36dfc7c6e7d11c0af1621b695a944 Crypto Donation Links: BTC: 1HewuvpGP1fwprdcg2yru5ss28tGCo4wg8 ETH: 0xC46CDe805aCC8e7507E53E36486C7D8600559d65 XMR: 42HvHqtwg2dcZqDfLZjK8Xc8LyFKN7i3XCipbVSFDJLVGsdUN5pT3e7LExz9QTaGzdGdrEohXzvkeFmdZK1MPGX92xqftUn
Views: 4367 Decypher Media
Bitcoin Protocol Explained #3 - Transactions
 
08:12
Bitcoin Protocol Paper Playlist: http://www.youtube.com/watch?v=UieiMU-ImvI&list=PLQVvvaa0QuDcq2QME4pfeh0cE71mkb_qz&feature=share All Bitcoin Videos Playlist: http://www.youtube.com/watch?v=UieiMU-ImvI&feature=share&list=PLQVvvaa0QuDebbCxrDPCux6SzC1RET4mF In this Bitcoin Protocol tutorial video, the Transactions section of the Bitcoin protocol paper is explained. Of course, however, with this proposed solution, we have another issue. We can for sure confirm that a user owns or at least owned a coin, and we can confirm the chain of owners, but we cannot confirm just yet that this coin was not double spent. Have no fear, this is coming! http://seaofbtc.com http://sentdex.com http://hkinsley.com https://twitter.com/sentdex Bitcoin donations: 1GV7srgR4NJx4vrk7avCmmVQQrqmv87ty6
Views: 9207 sentdex
HowTo Send a Bitcoin Transaction with JavaScript & Bitcore
 
13:16
http://bit.ly/bitcoincourse (full course) This will demo creating a Bitcoin address and transaction using JavaScript and the Bitcore.io library. Full source code is available at the link.
Views: 18583 CuriousInventor
Blockchain - How To Verify A Bitcoin Transaction And Get Your Hash ID
 
02:17
For more tips like these visit http://bodymindsuccess.com/bitcoin or subscribe to our channel
Views: 46927 Crypto Currency Wealth
Blockchain/Bitcoin for beginners 7: Blockchain header: Merkle roots and SPV transaction verification
 
39:40
How are transactions stored (and recorded) in the Blockchain blocks? Using a concept called a Merkle tree - in this video I break it down in depth with a simple example and show how a SPV node (Simple Payment Verification) node that does not keep a full copy of the blockchain transaction history - just the headers of the blocks - can verify from an adjacent (but not necessarily trusted) full node, which block a transaction is part of just from knowing the MERKLE PATH from the full node. http://chimera.labs.oreilly.com/books/1234000001802/ch07.html
Views: 11155 Matt Thomas
ep 13: How is bitcoin "locked" to an address - OP_CHECKSIG, locking scripts, signatures, UTXO chain
 
47:07
I've been meaning to make this video for a long time. It follows on from episode 12 which talks about locking and unlocking scripts and here we finish off the explanation with a look into how digital signatures are used to ensure that only the intended recipient of UTXO (unspent transaction output) can actually spend that UTXO in new transactions. Essentially the transaction is defined and then hashed and that hash is encrypted with the private key of the transaction creator (spender) - that becomes a signature of the transaction - and is used by all the nodes in the network to validate the transaction, and ensure that corresponding public key is the one used as the beneficiary of the output referenced in the transaction inputs.
Views: 3549 Matt Thomas
Bitcoin Lesson | Transactions
 
01:08:05
An explanation of how bitcoin transactions work. 01:27 - Transaction Basics ↳ 08:45 - Change ↳ 12:49 - Graph ↳ 15:10 - Coinbase Transaction ↳ 17:24 - Fees 20:00 - Transaction Data ↳ 35:22 - Signing ↳ 48:20 - Summary 54:20 - Live Example ↳ 1:02:45 - Code http://learnmeabitcoin.com/code - Transaction Builder & Command-Line Tools For more simple explanations of how bitcoin works, visit my website: http://learnmeabitcoin.com If you found this video helpful, please buy me a beer: 1AKDDsfTh8uY4X3ppy1m7jw1fVMBSMkzjP
Views: 1057 learnmeabitcoin
Use a Multisig Wallet to Protect your Bitcoin Transactions
 
03:27
As Bitcoin and other cryptocurrencies gain popularity as a mode of payment transfer, it has become common for the average Bitcoin user to be scammed by an anonymous identity who requests payment for some work is then never heard from again. . The decentralized nature of cryptos certainly has a tradeoff – unlike a credit card or bank transaction that can be reverted, a cryptocurrency transfer once confirmed is permanently recorded on the Blockchain. This is where multi-signature (multisig) wallets come to our rescue.. A multisig wallet is a special bitcoin wallet that requires more than one private key to sign transactions. Most multi-signature setups usually involve three parties – the sender of the payment, the recipient, and an escrow agent. Each of the three parties holds one private key, and to send any transaction, at least two private keys must be used.. Typically, escrow agents are trusted members of the Bitcoin community or registered entities who arbitrate any disputes that may arise. Therefore, the buyer is protected in case the seller turns out to be fraudulent, and the seller, too, is assured of payment even if the buyer refuses to pay.. CREATING A MULTISIG WALLET. There are many ways to create a multisig wallet. In fact, most Bitcoin clients support the multisig protocol. Electrum and Armoury are used by many crypto holders because they have provisions for advanced settings like custom fees etc. which are great for power users. . BitGo is another popular option for those who prefer a web-based client. In my opinion, however, CoPay offers the most streamlined, easy to use interface, that is usable by anyone, even a new Bitcoin user. So for the purposes of this tutorial, I will be using. Step 1: Download CoPay. Head over to the CoPay website and download the appropriate installer for your platform. A great advantage of using CoPay is its support for nearly all desktop and mobile platforms (iOS and Android included).. Step 2: Start by setting up your personal wallet. Open the installed app, and run through the quick setup to create your personal wallet. This will involve typing in an email address for transaction notifications, and noting down a mnemonic phrase that can be used as a backup in case CoPay is accidentally deleted from your computer.. Step 3: Create a Shared Wallet. Multisig wallets are called ‘Shared Wallets’ in CoPay. Once your personal wallet is set up, click on the shared wallet option on the CoPay home screen to create a multisig wallet. You will be presented with a screen where you can configure the wallet with the number of co-payers, the number of signatures required etc. depending on your needs.. Step 4: Share the CoPay invite with others. The last step is to share your multisig wallet with the 2 other parties. Send them the CoPay code displayed or ask them to scan the QR code. That’s it! Your CoPay escrow is set up! Now everytime someone requests a payment, you will receive a notification to confirm the transactio
What is Multisig Technology?
 
02:57
How do you keep your digital currency safe? Jerry Brito, Executive Director of the Coin Center, explains how multisignature technology provides increased security for digital currencies such as Bitcoin. As always, the Federalist Society takes no position on particular legal or public policy issues; all expressions of opinion are those of the speaker. Follow Jerry Brito on Twitter: @jerrybrito https://twitter.com/jerrybrito Related links: What is Multi-Sig, and What Can It Do? https://coincenter.org/entry/what-is-multi-sig-and-what-can-it-do The best multisignature wallets for 2016 https://bravenewcoin.com/news/the-best-multisignature-wallets-for-2016/ The Wretched, Endless Cycle of Bitcoin Hacks https://www.bloomberg.com/news/articles/2016-08-17/the-wretched-endless-cycle-of-bitcoin-hacks
Views: 43436 The Federalist Society
Blockchain/Bitcoin for beginners 8: Bitcoin addresses, public key hash, P2PKH transactions
 
23:28
Before we delve into the inner workings of a bitcoin transaction I wanted to explain how the actual bitcoin address is derived from the public key which in turn is derived from the private key. I take through step by step all the steps required to derived the checksums etc and show with a real example of a real bitcoin transaction. Also discuss why checksums are included in Bitcoin addresses in order to eliminate the possibility of characters being corrupted, or modified in transit. This is the cool tool for converted from base 58 encoded value to hex value. http://lenschulwitz.com/base58 Good link talking about base 58 encoding. https://en.bitcoin.it/wiki/Base58Check_encoding
Views: 10322 Matt Thomas
Dev++ | Jimy Song - Foundational Math, ECDSA and Transactions
 
01:43:32
Jimmy Song explains the basics of cryptography that serves as a foundation for Bitcoin transactions. This course provides in-depth coverage of Elliptic Curve Digital Signature Algorithm (ECDSA), how ECDSA functions and how it is used to provide signing and verification of Bitcoin transactions. After covering the basics, Jimmy dives into and explains Bitcoin transaction data structure, including Bitcoin scripting opcodes - how these transactions are formed and interpreted by Bitcoin nodes. This session contains multiple sections at following timestamps: Finite Fields - https://youtu.be/e6voIwB-An4?t=4m50s Elliptic Curves - https://youtu.be/e6voIwB-An4?t=21m11s Elliptic Curves over Finite Fields - https://youtu.be/e6voIwB-An4?t=32m32s Mathematical Group - https://youtu.be/e6voIwB-An4?t=37m59s Bitcoin Addresses - https://youtu.be/e6voIwB-An4?t=50m08s ECDSA - https://youtu.be/e6voIwB-An4?t=57m42s Bitcoin Transactions - https://youtu.be/e6voIwB-An4?t=1h10m14s Bitcoin Scripts - https://youtu.be/e6voIwB-An4?t=1h17m27s Transaction Validation - https://youtu.be/e6voIwB-An4?t=1h25m Pay to Script Hash - https://youtu.be/e6voIwB-An4?t=1h29m27s To complete tasks in this course, you will need to setup the appropriate python environment as follows: Install python3, virtualenv, git $ git clone http://github.com/bitcoinedge/devplusplus $ cd devplusplus $ virtualenv -p python3 .venv $ . .venv/bin/activate $ pip install -r requirements.txt $ jupyter notebook Your browser should open up a jupyter notebook For additional information, please visit http://bitcoinedge.org If you are a professional interested in working in blockchain ecosystem, please create a profile on http://bitcoinedge.org and we will share your profile with our sponsors. If you are a company interested in hiring blockchain developers for full-time or contractual basis, please email us at contact@bitcoinedge.org
Views: 2014 Bitcoin Edge
Bitcoin Q&A: Schnorr signatures and the privacy roadmap
 
16:29
How important are privacy improvements to Bitcoin in the roadmap? How will second layers and atomic swaps help with this? When will Schnorr signatures / signature aggregation be added to Bitcoin? What are Taproot and Graftroot? Will it be done through a soft or hard fork? Should we keep transaction transparency instead of adding privacy features? Watch Pieter Wuille's presentation - https://youtu.be/YSUVRj8iznU Schnorr signature BIP - https://github.com/sipa/bips/blob/bip-schnorr/bip-schnorr.mediawiki CORRECTION / CLARIFICATION: At 3:47, I mention that Schnorr signatures had to overcome "patent encumbrances" and guessed that the patent expired somewhere around 2010. The precise expiration date of the U.S. Patent (No. 4,995,082) was February 2008. At 4:22, I say that ECDSA and EC-Schnorr are based on the difficulty of solving the discrete logarithm problem over a prime-order field. While this is true for the digital signature algorithm (DSA), ECDSA and Schnorr are based on the discrete log problem over an elliptic curve group. (h/t 'Daira Hopwood') These questions were part of the monthly live Patreon Q&A session in July and the Denver event as part of 'The Internet of Money Tour' at the Hilton Denver Inverness, which took place on July 28th and August 6th 2018 respectively. If you want early-access to talks and a chance to participate in the monthly live Q&As with Andreas, become a patron: https://www.patreon.com/aantonop RELATED: Worse than Useless: Financial Surveillance - https://youtu.be/n4F-h4xuXMk Money as a System-of-Control - https://youtu.be/FyK4P7ZdOK8 The Stories We Tell About Money - https://youtu.be/ONvg9SbauMg Bitcoin: Privacy, Identity, Surveillance and Money - https://youtu.be/Vcvl5piGlYg ADISummit: Self-Sovereign Identity Panel - https://youtu.be/DZbyiJqKT8c How is fungibility tied to privacy? - https://youtu.be/VuI-8EwqIS8 Public keys versus addresses - https://youtu.be/8es3qQWkEiU Re-using addresses - https://youtu.be/4A3urPFkx8g Coin selection and privacy - https://youtu.be/3Ck683CQGAQ Airdrop coins and privacy implications - https://youtu.be/JHRnqJJ0rhc Wallet design and mass adoption - https://youtu.be/WbZX6BDZJHc How do I choose a wallet? - https://youtu.be/tN6b62sEpsY Using paper wallets - https://youtu.be/cKehFazo8Pw Exchanges, identity, and surveillance - https://youtu.be/TVFy8xXfxAA The price of losing privacy - https://youtu.be/2G8IgiLbT_4 Layered scaling and privacy - https://youtu.be/4w-bjUhpf_Q Lightning and onion routing - https://youtu.be/D-nKuInDq6g What is the roadmap? - https://youtu.be/5Eoj_sKyC90 SegWit and fork research - https://youtu.be/OorLoi01KEE MimbleWimble and Schnorr signatures - https://youtu.be/qloq75ekxv0 Block capacity and embedded data - https://youtu.be/JXt0v54nojI Mixing services - https://youtu.be/rKoMvOH4zoY Borderless money - https://youtu.be/EZh1-ZqffOw Andreas M. Antonopoulos is a technologist and serial entrepreneur who has become one of the most well-known and respected figures in bitcoin. Follow on Twitter: @aantonop https://twitter.com/aantonop Website: https://antonopoulos.com/ He is the author of two books: “Mastering Bitcoin,” published by O’Reilly Media and considered the best technical guide to bitcoin; “The Internet of Money,” a book about why bitcoin matters. THE INTERNET OF MONEY, v1: https://www.amazon.co.uk/Internet-Money-collection-Andreas-Antonopoulos/dp/1537000454/ref=asap_bc?ie=UTF8 [NEW] THE INTERNET OF MONEY, v2: https://www.amazon.com/Internet-Money-Andreas-M-Antonopoulos/dp/194791006X/ref=asap_bc?ie=UTF8 MASTERING BITCOIN: https://www.amazon.co.uk/Mastering-Bitcoin-Unlocking-Digital-Cryptocurrencies/dp/1449374042 [NEW] MASTERING BITCOIN, 2nd Edition: https://www.amazon.com/Mastering-Bitcoin-Programming-Open-Blockchain/dp/1491954388 Translations of MASTERING BITCOIN: https://bitcoinbook.info/translations-of-mastering-bitcoin/ Subscribe to the channel to learn more about Bitcoin & open blockchains! Music: "Unbounded" by Orfan (https://www.facebook.com/Orfan/) Outro Graphics: Phneep (http://www.phneep.com/) Outro Art: Rock Barcellos (http://www.rockincomics.com.br/)
Views: 9125 aantonop
How To Create a Secure Multisignature Wallet and Send Multisignature Transactions
 
03:30
Whether you want to add security or accountability to your bitcoin transactions or share a bitcoin wallet across multiple device, the BitPay multisignature wallet is a great option. Watch to learn how to get started.
Views: 4206 BitPay
Getting the ECDSA Z Value from a Single Input Multi Signature Transaction
 
07:02
In this video I demonstrate getting the ECDSA Z value from a bitcoin transaction containing a multi signature input. I also show the R and S values. The ECDSA R, S and Z values are used throughout the many layers of bitcoin to validate a transaction. The Z value is also sometimes referred to as the signed message. Transactions that don't contain valid inputs can be safely ignored and the Z value is one of the properties that is used during the transaction validation process. The urls I used in the video are, The reference transaction - https://2coin.org/index.html?txid=bf8f4a6be134aa673727f667d6d5ea8d8baad5249611900cdc8e83dae2a4a365 Bitcoin wiki Script documentation -https://en.bitcoin.it/wiki/Script#Constants Double SHA256 form - https://2coin.org/doublesha256.html
Views: 827 seanwasere ytbe
SF Bitcoin Devs Seminar: Key Tree Signatures
 
53:49
Pieter Wuille, Bitcoin Core Developer and Blockstream Co-Founder, spoke about Key Tree Signatures. Bitcoin supports multisig transaction outputs, which require more than a single signature to unlock. These can be used for low-trust escrow, two-factor security (signatures by two devices) and funds with shared control. However, Bitcoin's multisig support is based on OP_CHECKMULTISIG internally, which has significant limitations. For one, it only supports up to 15 keys, and has a high verification cost to the network. If we restrict the problem to 1-of-N multisig (as opposed to K-of-N), all we need is to be able to cheaply prove that a particular given key is part of a set that is known in advance, plus verify a signature by that key. For the first part, we could use a Merkle tree, if we could implement Merkle branch verification inside script. This is not possible in Bitcoin because it needs OP_CAT which was disabled years ago. In Elements Alpha, a first demo sidechain by Blockstream, this opcode was reenabled, making cheap 1-of-N possible. Alpha has another change, namely using Schnorr signatures rather than ECDSA signatures. Schnorr signatures support native K-of-K multisig, with the same efficiency as a single 1-of-1 key. We can combine these two changes to support K-of-N: build a Merkle tree where every leaf is a Schnorr combination of a set of K of the N keys. This results in signatures that are at worst half the size as OP_CHECKMULTISIG ones, and are far faster to verify, We can even go further, and introduce a small language for describing sets of permissible keys for signing, as the approach above is not limited to just K-of-N. For more information see: https://blockstream.com/2015/08/24/treesignatures/
Views: 1347 SF Bitcoin Developers
Creating pre-signed bitcoin transactions
 
08:48
In this video, I show how to create a pre-signed transaction that can be broadcast to the bitcoin network at a later time. Useful in situations where you would need a send a transaction but wouldn't have access to your wallet either for security or convenience reasons.
Views: 1518 Bitcoin Hacks
Getting the ECDSA Z Value from a Bitcoin Multiple Input Transaction
 
09:09
In this video I demonstrate getting the ECDSA Z value from a bitcoin transaction with 2 inputs. I also show the R and S values. The ECDSA R, S and Z values are used throughout the many layers of bitcoin to validate a transaction. The Z value is also sometimes referred to as the signed message. Transactions that don't contain valid inputs can be safely ignored and the Z value is one of the properties that is used during the transaction validation process. The urls I show in this video are https://2coin.org/index.html?txid=9ec4bc49e828d924af1d1029cacf709431abbde46d59554b62bc270e3b29c4b1 https://2coin.org/pubkeyToHash160.html https://2coin.org/doublesha256.html
Views: 1192 seanwasere ytbe
Automatic Escrow with Bitcoin
 
03:36
Trustatom uses multi-signature bitcoin addresses to provide cheap escrow to anyone with bitcoin. This is the first example of a smart contract, made possible by programmable money. Trustatom is no longer. While CoPay wallet is not explicitly for doing escrow, it allows you to easily create, fund, and spend from m-of-n multisignature wallets. Subscribe to support bitcoin media and follow me on twitter @bitcoin3000
Views: 4273 Alex Millar
How To Create a Multisig Address and Spend From It
 
15:59
CheatSheet: http://pastebin.com/nw2Tqg3U How to create a new multisig bitcoin address yourself with bitcoin core client and spend from it using raw transactions. BTC: 1NPrfWgJfkANmd1jt88A141PjhiarT8d9U Follow me on twitter: https://twitter.com/coinableS How to create a multisig wallet? How do I make a multisig address? Bitcoin Multisig
Views: 10174 m1xolyd1an
How Does Monero Work?
 
23:05
Monero is a cryptocurrency that enables private transactions. That means the sender, receiver, and transaction amount are not publicly viewable, unlike Bitcoin's blockchain. Monero's transactions stay private using the technology of ring signatures, ringCT, stealth addresses, and I2P routing. I'll explain how all of this works in this video. I do not condone the use of this technology for illegal transactions. This is powerful stuff, ideally, we start using this as a stepping stone towards a world where we get paid for our transactional data (and all the rest of our data). You'll find the jupyter notebook for this video and the associated code that I demo in the github link below. Code for this video: https://github.com/llSourcell/how_does_monero_work More learning resources: https://getmonero.org/ https://github.com/monero-project/monero https://www.monero.how/tutorial-how-to-use-the-monero-gui-wallet https://www.monero.how/tutorial-how-to-mine-monero https://99bitcoins.com/beginners-guide-to-monero/ Please Subscribe! And like. And comment. That's what keeps me going. Want more inspiration & education? Connect with me: Twitter: https://twitter.com/sirajraval Facebook: https://www.facebook.com/sirajology Instagram: https://www.instagram.com/sirajraval/ Join us in the Wizards Slack channel: http://wizards.herokuapp.com/ And please support me on Patreon: https://www.patreon.com/user?u=3191693
Views: 67510 Siraj Raval
IOTA tutorial 10: Transaction and Bundle
 
21:01
If you like this video and want to support me, go this page for my donation crypto addresses: https://www.youtube.com/c/mobilefish/about This is part 10 of the IOTA tutorial. In this video series different topics will be explained which will help you to understand IOTA. It is recommended to watch each video sequentially as I may refer to certain IOTA topics explained earlier. The squares in the Tangle represents transactions and each NEW transaction should reference transactions which have no other transactions referencing them. These non referenced transactions are called tips (tip 0 and tip 1). Each transaction consists of a bundle of transactions. An example of an IOTA transaction where 3 IOTA’s are transferred from Alice's address to Bob's address: https://www.mobilefish.com/download/iota/transactions_in_bundle_example1.txt A transaction consists of a bundle of transactions: currentIndex 0 refers to transaction 0, currentIndex 1 refers to transaction 1, etc.. All these transactions have the same bundle hash. All transactions in the same bundle should be treated as an atomic unit. It means that either all transactions of a bundle are confirmed, or none of them are confirmed. Every transaction in the bundle requires it own PoW, see the different nonces in the transactions. There can be 3 different types of transactions inside a bundle: - Output transactions Transactions where IOTA’s are send to one or multiple addresses. The IOTA light wallet can only send to one address. These transactions are easily recognised because the transaction value is always greater than 0 and the address does not belong the sender. - Input transactions There are two types of input transactions: * Input transactions where the value is negative. These are the transactions where the complete balance from that address is spent. * Input transactions where the value is greater than 0. These are the transactions where unspent/not used IOTA’s are send to a new change address in the senders wallet. - Meta transactions Zero value transactions are meta transactions. The signatureMessageFragment of these transactions could either hold a signature or a message fragment. Transaction examples: https://www.mobilefish.com/download/iota/transactions_in_bundle_example1.txt https://www.mobilefish.com/download/iota/transactions_in_bundle_example2.txt https://www.mobilefish.com/download/iota/transactions_in_bundle_example3.txt https://www.mobilefish.com/download/iota/transactions_in_bundle_example5.txt By increasing the security level you increase the key size, meaning you increase the private key size. Depending on the key size, this signature is fragmented and stored in 1, 2 or 3 transactions. Wallet 1, using security level 1, the signature is stored in 1 transaction: https://www.mobilefish.com/download/iota/transactions_in_bundle_security_level1.txt Wallet 2, using security level 2, the signature is fragmented and stored in 2 transactions: https://www.mobilefish.com/download/iota/transactions_in_bundle_security_level2.txt Wallet 3, using security level 3, the signature is fragmented and stored in 3 transactions: https://www.mobilefish.com/download/iota/transactions_in_bundle_security_level3.txt By increasing the security level you increase the signature size and thus the number of transactions needed to store the signature. IOTA signatures are larger than Bitcoin signatures due to IOTA's use of Winternitz one-time signatures to gain quantum resistance. Each single transaction inside a bundle consists of 2673 trytes and much of it is taken by the signatureMessageFragment which has a size of 2187 trytes (approx 82%). A single transaction inside a bundle requires 2673 trytes or ~1.55 kBytes. A bundle can have one transaction, for example when you attach an address to the Tangle. A bundle can have an X number of transactions. For example: Alice has a wallet (using security level 2) with address 0 to address 99 with each address having one IOTA. When Alice transfers her complete wallet balance to Bob, she creates a transaction bundle containing 201 transactions: 1 transaction to Bob, 100 transactions withdrawing 1 IOTA from each address and 100 meta transactions to store the second signature fragment. Each transaction inside the bundle requires a PoW. Let assume a PoW takes 20 seconds per transaction. Please note: This 20 sec is arbitrary chosen! In this example the total time to create the bundle, takes: 201 transactions x 20 sec / tx = 67 minutes. You can easily create a transaction bundle containing lots of transactions. However watch out for the Proof of Work. Check out all my other IOTA tutorial videos: https://goo.gl/aNHf1y Subscribe to my YouTube channel: https://goo.gl/61NFzK The presentation used in this video tutorial can be found at: https://www.mobilefish.com/developer/iota/iota_quickguide_tutorial.html #mobilefish #howto #iota
Views: 2444 Mobilefish.com
Bitcoin - Transaction records
 
11:32
The basic mechanics of a bitcoin transaction between two parties and what is included within a given bitcoin transaction record. More free lessons at: http://www.khanacademy.org/video?v=9-9_v1wSPBQ Video by Zulfikar Ramzan. Zulfikar Ramzan is a world-leading expert in computer security and cryptography and is currently the Chief Scientist at Sourcefire. He received his Ph.D. in computer science from MIT.
Views: 110535 Khan Academy
What is a Bitcoin Transaction?
 
06:37
In this video I explain what a Bitcoin transaction is, what the contents of a Bitcoin transaction are and I present an example of sending and receiving bitcoins. Featuring content a sample lesson taken from the Bitcoin Advanced Level: Transactions course from Blockchain Institute of Technology (https://BlockchainInstituteofTechnology.com) at: https://courses.blockchaininstituteoftechnology.com/courses/bitcoin-advanced-transactions Sign up to receive George Levy's FREE email newsletter and a video email course on blockchain, Bitcoin and cryptocurrency ($47 Value yours free) at: https://GeorgeLevy.com/Free Special offer for George Levy channel viewers, open your own Bitcoin wallet for Free and get $10 bonus in Bitcoin: https://blockchaininformer.com/btcwallet
Views: 1942 George Levy
Bitcoin M-of-N Multisig Addresses - Well Tempered Hacker
 
20:40
Standard bitcoin transactions involve payment to an address which requires a signature from one private key to spend. With multi-signature addresses, M of N transactions are possible. In this episode we will create a multi-signature address which requires two of three signatures to spend. This could be useful for securing bitcoin in multiple locations reducing the "all or nothing" risk of loosing a private key. One example use of this is in securing some amount of bitcoin offline. You might first generate three private keys and from them generate a 2 of 3 multisig address. At this point, the address is worthless. Then you might print out those private keys and the redeem script onto three separate pieces of paper and destroy any digital copy. Next you might send two of those pieces of paper to two different friends of yours and keep the third in a safe place yourself. Remember, there is no value on the multisig address yet so if they get lost in transit or for some reason you believe the papers didn't make it to their destinations safely, you just start over. With our keys safely in three separate locations, you might transfer some bitcoin to the multisig address, loading up your offline wallet. Some time goes by and you might want to gain access to your bitcoin. You create a spend transaction sending the value to some other online wallet. This transaction isn't valid yet because nobody has signed it so it is safe to send via email to one of your friends. They pull out the piece of paper you sent them, type in the private key adding their signature to the transaction. The transaction is still not yet valid so they email it back to you without worry. You then might decide to add your signature to the transaction making it valid. Again, the transaction would be safe to email because any attempt to change the transaction redirecting it to some other address would invalidate the whole thing. After deciding this is still what you wanted, you might decide to transmit this previously completely offline transaction on the network which would spend the funds away from the multisig address. This is very similar to how many online wallet provider's "vault" features work. However, doing this yourself removes the requirement to trust a possibly disinterested third party. As with anything you do yourself, however, there wouldn't be a third party to blame if you messed things up. (I'm not responsible for any bitcoin you loose trying to get this working!) There are risks in either strategy. The software used in this demo is available here: https://github.com/anders94/bitcoin-2-of-3-multisig
Views: 3896 Anders Brownworth
Offline Transactions with Bitcoin
 
13:12
Super paranoid way to do offline transactions. Update Jan-2018: I now use coinb.in to do the transaction creating and signing. Much better. Uses: http://offlinewallet.appspot.com/ https://blockchain.info/pushtx Tips: 1JS6Cm1J5cBwLb4fBmkrFYKZ5smgj9BJGK
Views: 2416 Matthew Smith
How Bitcoin Works in 5 Minutes. (Technical)
 
05:26
How does Bitcoin work? This is a question that often causes confusion. Here's a quick explanation! The basics for a new user As a new user, you can get started with Bitcoin without understanding the technical details. Once you have installed a Bitcoin wallet on your computer or mobile phone, it will generate your first Bitcoin address and you can create more whenever you need one. You can disclose your addresses to your friends so that they can pay you or vice versa. In fact, this is pretty similar to how email works, except that Bitcoin addresses should only be used once. Bitcoin Balances - block chain The block chain is a shared public ledger on which the entire Bitcoin network relies. All confirmed transactions are included in the block chain. This way, Bitcoin wallets can calculate their spendable balance and new transactions can be verified to be spending bitcoins that are actually owned by the spender. The integrity and the chronological order of the block chain are enforced with cryptography. Transactions - private keys A transaction is a transfer of value between Bitcoin wallets that gets included in the block chain. Bitcoin wallets keep a secret piece of data called a private key or seed, which is used to sign transactions, providing a mathematical proof that they have come from the owner of the wallet. The signature also prevents the transaction from being altered by anybody once it has been issued. All transactions are broadcast between users and usually begin to be confirmed by the network in the following 10 minutes, through a process called mining. Processing - mining Mining is a distributed consensus system that is used to confirm waiting transactions by including them in the block chain. It enforces a chronological order in the block chain, protects the neutrality of the network, and allows different computers to agree on the state of the system. To be confirmed, transactions must be packed in a block that fits very strict cryptographic rules that will be verified by the network. These rules prevent previous blocks from being modified because doing so would invalidate all following blocks. Mining also creates the equivalent of a competitive lottery that prevents any individual from easily adding new blocks consecutively in the block chain. This way, no individuals can control what is included in the block chain or replace parts of the block chain to roll back their own spends.
Views: 31489 Ledger Wallet
Creating and Using Multisignature Wallets (Litecoin/Bitcoin)
 
04:09
How to create and send funds from a multi signature electrum wallet 🎵 Music: Rick Wade - Meditation (Matsa Remix)
Views: 8392 Franklyn [Litecoin]
Blockchain tutorial 27: Bitcoin raw transaction and transaction id
 
12:17
This is part 27 of the Blockchain tutorial. This tutorial explains: - What Bitcoin raw transaction is. - Shows an example of a raw transaction using the very first transaction on the Genesis block. - What the difference is between big endian and little endian. - What a satoshi is. - What a Bitcoin transaction id or hash is and what its purpose is. - How to calculate the transaction id. In this video series different topics will be explained which will help you to understand blockchain. Bitcoin released as open source software in 2009 is a cryptocurrency invented by Satoshi Nakamoto (unidentified person or group of persons). After the introduction of Bitcoin many Bitcoin alternatives were created. These alternate cryptocurrencies are called Altcoins (Litecoin, Dodgecoin etc). Bitcoin's underlying technology is called Blockchain. The Blockchain is a distributed decentralized incorruptible database (ledger) that records blocks of digital information. Each block contains a timestamp and a link to a previous block. Soon people realises that there many other use cases where the Blockchain technology can be applied and not just as a cryptocurrency application. New Blockchain platforms were created based on the Blockchain technology, one of which is called Ethereum. Ethereum focuses on running programming code, called smart contracts, on any decentralized application. Using the new Blockchain platforms, Blockchain technology can be used in supply chain management, healthcare, real estate, identity management, voting, internet of things, etcetera, just to name a few. Today there is a growing interest in Blockchain not only in the financial sector but also in other sectors. Explaining how Blockchain works is not easy and for many the Blockchain technology remains an elusive concept. This video series tries to explain Blockchain to a large audience but from the bottom up. Keywords often used in Blockchain conversation will be explained. Each Blockchain video is short and to the point. It is recommended to watch each video sequentially as I may refer to certain Blockchain topics explained earlier. Check out all my other Blockchain tutorial videos https://goo.gl/aMTFHU Subscribe to my YouTube channel https://goo.gl/61NFzK The presentation used in this video tutorial can be found at: http://www.mobilefish.com/developer/blockchain/blockchain_quickguide_tutorial.html The 3 links mentioned in the video are: - The bitcoin_genesis_raw_tx.txt file http://www.mobilefish.com/download/cryptocurrency/bitcoin_genesis_raw_tx.txt - The Bitcoin protocol: https://en.bitcoin.it/wiki/Protocol_documentation#tx - The block explorer used in the video: https://blockchain.info/ The python script to calculate the transaction id: http://www.mobilefish.com/download/cryptocurrency/calculate_txid.py.txt The brainwallet tool to convert the raw transaction into a more readable text: http://www.mobilefish.com/services/cryptocurrency/brainwallet.html #mobilefish #blockchain #bitcoin #cryptocurrency #ethereum
Views: 4784 Mobilefish.com
Bitcoin Q&A: MimbleWimble and Schnorr signatures
 
05:41
What is MimbleWimble, Schnorr signatures, and what are the implications for privacy and the block size debate? MimbleWimble: https://scalingbitcoin.org/papers/mimblewimble.pdf Schnorr signatures: https://eprint.iacr.org/2018/068 This was part of the first monthly live Patreon Q&A session on November 27th, 2017. If you want early-access to talks and a chance to participate in the monthly live Q&As with Andreas, become a patron: https://www.patreon.com/aantonop RELATED: Advanced Bitcoin Scripting: Transactions and Multisig - https://youtu.be/8FeAXjkmDcQ Advanced Bitcoin Scripting: SegWit, Consensus, and Trustware - https://youtu.be/pQbeBduVQ4I Lightning and onion routing - https://youtu.be/D-nKuInDq6g Scaling complex systems - https://youtu.be/dm9m1oQr6Ks Layered scaling and privacy - https://youtu.be/4w-bjUhpf_Q The price of losing privacy - https://youtu.be/2G8IgiLbT_4 The war on cash and crypto - https://youtu.be/BAlRKfvBnvw Andreas M. Antonopoulos is a technologist and serial entrepreneur who has become one of the most well-known and respected figures in bitcoin. Follow on Twitter: @aantonop https://twitter.com/aantonop Website: https://antonopoulos.com/ He is the author of two books: “Mastering Bitcoin,” published by O’Reilly Media and considered the best technical guide to bitcoin; “The Internet of Money,” a book about why bitcoin matters. THE INTERNET OF MONEY, v1: https://www.amazon.co.uk/Internet-Money-collection-Andreas-Antonopoulos/dp/1537000454/ref=asap_bc?ie=UTF8 [NEW] THE INTERNET OF MONEY, v2: https://www.amazon.com/Internet-Money-Andreas-M-Antonopoulos/dp/194791006X/ref=asap_bc?ie=UTF8 MASTERING BITCOIN: https://www.amazon.co.uk/Mastering-Bitcoin-Unlocking-Digital-Cryptocurrencies/dp/1449374042 [NEW] MASTERING BITCOIN, 2nd Edition: https://www.amazon.com/Mastering-Bitcoin-Programming-Open-Blockchain/dp/1491954388 Subscribe to the channel to learn more about Bitcoin & open blockchains! Music: "Unbounded" by Orfan (https://www.facebook.com/Orfan/) Outro Graphics: Phneep (http://www.phneep.com/) Outro Art: Rock Barcellos (http://www.rockincomics.com.br/)
Views: 22281 aantonop
Bitcoin Q&A: What is a private key?
 
18:18
What is a private key? How are they generated and formatted? Are private keys transmitted when you make a transaction? What are the chances of collision? Will quantum computing making it easy to guess private keys? Does implementing quantum-proof algorithms require an overhaul of the code? Learn more from the following chapters of 'Mastering Bitcoin': https://github.com/bitcoinbook/bitcoinbook/blob/f8b883dcd4e3d1b9adf40fed59b7e898fbd9241f/ch04.asciidoc https://github.com/bitcoinbook/bitcoinbook/blob/f8b883dcd4e3d1b9adf40fed59b7e898fbd9241f/ch05.asciidoc Key to address code: https://github.com/bitcoinbook/bitcoinbook/blob/35f1c62f192dd0eaf1b1c462f88a46e0f5942e16/code/key-to-address-ecc-example.py These questions are from the MOOC 9.3 and 9.4 sessions, as well as the (rescheduled) April Patreon Q&A session, which took place on March 2nd, March 9th, and May 5th 2018 respectively. Andreas is a teaching fellow with the University of Nicosia. The first course in their Master of Science in Digital Currency degree, DFIN-511: Introduction to Digital Currencies, is offered for free as an open enrollment MOOC course to anyone interested in learning about the fundamental principles. If you want early-access to talks and a chance to participate in the monthly live Q&As with Andreas, become a patron: https://www.patreon.com/aantonop RELATED: Bitcoin: Where the Laws of Mathematics Prevail - https://youtu.be/HaJ1hvon0E0 Advanced Bitcoin Scripting Part 1: Transactions & Multisig - https://youtu.be/8FeAXjkmDcQ Advanced Bitcoin Scripting Part 2: SegWit, Consensus, and Trustware - https://youtu.be/pQbeBduVQ4I Cryptographic primitives - https://youtu.be/RIckQ6RBt5E Nonces, mining, and quantum computing - https://youtu.be/d4xXJh677J0 Public keys vs. addresses - https://youtu.be/8es3qQWkEiU Re-using addresses - https://youtu.be/4A3urPFkx8g What happens to our bitcoins during a hard fork? - https://youtu.be/sNR76fWd7-0 How do mnemonic seeds work? - https://youtu.be/wWCIQFNf_8g Multi-signature and distributed storage - https://youtu.be/cAP2u6w_1-k What is Segregated Witness? - https://youtu.be/dtOjjB4mD8k SegWit and fork research - https://youtu.be/OorLoi01KEE Forkology: A Study of Forks for Newbies - https://youtu.be/rpeceXY1QBM MimbleWimble and Schnorr signatures - https://youtu.be/qloq75ekxv0 Protocol development security - https://youtu.be/4fsL5XWsTJ4 Migrating to post-quantum cryptography - https://youtu.be/dkXKpMku5QY Andreas M. Antonopoulos is a technologist and serial entrepreneur who has become one of the most well-known and respected figures in bitcoin. Follow on Twitter: @aantonop https://twitter.com/aantonop Website: https://antonopoulos.com/ He is the author of two books: “Mastering Bitcoin,” published by O’Reilly Media and considered the best technical guide to bitcoin; “The Internet of Money,” a book about why bitcoin matters. THE INTERNET OF MONEY, v1: https://www.amazon.co.uk/Internet-Money-collection-Andreas-Antonopoulos/dp/1537000454/ref=asap_bc?ie=UTF8 [NEW] THE INTERNET OF MONEY, v2: https://www.amazon.com/Internet-Money-Andreas-M-Antonopoulos/dp/194791006X/ref=asap_bc?ie=UTF8 MASTERING BITCOIN: https://www.amazon.co.uk/Mastering-Bitcoin-Unlocking-Digital-Cryptocurrencies/dp/1449374042 [NEW] MASTERING BITCOIN, 2nd Edition: https://www.amazon.com/Mastering-Bitcoin-Programming-Open-Blockchain/dp/1491954388 Translations of MASTERING BITCOIN: https://bitcoinbook.info/translations-of-mastering-bitcoin/ Subscribe to the channel to learn more about Bitcoin & open blockchains! Music: "Unbounded" by Orfan (https://www.facebook.com/Orfan/) Outro Graphics: Phneep (http://www.phneep.com/) Outro Art: Rock Barcellos (http://www.rockincomics.com.br/)
Views: 6799 aantonop
Bitcoin Transaction Basics
 
11:02
Basics of Bitcoin Transactions , how digital signatures enable transfer of bitcoin. Bitcoin peer-to-peer network. Jan 3 2009 - Satoshi created bitcoins from scratch
Views: 9 Jay Berg
How To Get Your Bitcoin Transaction Confirmed with CPFP
 
07:15
In this video I will show you how to use Child Pays For Parent (CPFP) to get an old unconfirmed transaction to confirm in under an hour. You will need to be one of the receiving parties of the transaction and have access to the receiving private key.
Views: 38510 m1xolyd1an
Blockchain 101 Ep 63 - What is Segregated Witness SegWit
 
00:59
SegWit is a solution to increase the scalability of blockchain and has already been successfully implemented on Litecoin and Bitcoin. Currently, every block not only record every transaction details, it also includes details such as the timestamp, Bitcoins transferred, or the transaction’s digital signature, to verify the legitimacy of each transaction. Digital signatures are required for verification when miners process transactions, before adding the transaction to the block. However, to the regular user, he is only concerned with how much assets he has in his accounts, not verifying every transaction. Segwit removes the digital signature information within a block, allowing each block to hold more transactions, achieving the goal of scalability. Huobi Global Exchange: https://www.huobi.com Follow us on: Blog: https://blog.huobi.com/ Facebook: https://www.facebook.com/huobiglobalofficial Instagram: https://www.instagram.com/huobiglobalofficial Medium: https://medium.com/@huobiglobal Telegram: https://t.me/huobiglobalofficial Twitter: https://twitter.com/HuobiGlobal Reddit: https://www.reddit.com/r/HuobiGlobal/ Youtube: https://www.youtube.com/HuobiGlobal
Views: 177 Huobi Global
ep 12: Bitcoin locking and unlocking scripts - syntax and basic concepts
 
43:40
In this video we introduce "script" - Bitcoin's lightweight stack-based language which all nodes run to validate new transactions to see whether the referenced outputs referenced in the input section are correctly "unlocked" by the inputs..... We continue the analogy from the previous video in which we first use transaction paper documents to audit cash (coins and notes) changing hands in the outside world, and then discuss how the system can be modified/enhanced slightly to allow us to dispense with cash altogether and use the transaction documents to store, and transfer value...this of course depends on their being an underlying safe, trustless, tamper-proof store for these documents which is instantaneously visible to everyone (public)....in the real world this would be analogous to there being 1000's of boxes of copies of the paper transactions all over the world for people to inspect.
Views: 3829 Matt Thomas
Public and Private Key- How it works in Bitcoin.
 
16:31
RSA Public Key Encryption Algorithm (cryptography). How & why it works. See my blog for more about bitcoin and it's emeging opportunity http://bestbitcoinprograms.com/ -------------------- Buy bitcoin and other 7 blue chips coin from your Card or Bank transfer instantly. It is the most reliable and convenient way to buy crypto right now. It’s been since 2013. Buying your first Bitcoin (any country and method) & Selling Bitcoin back to FIAT currency. Just check it out:- https://cex.io/r/0/up104639387/0/
Views: 14811 ABI International
What is the merkle tree in Bitcoin?
 
03:53
Explanation of cryptographic hash: https://youtu.be/IVqD-_QskW0?t=1m13s 13uJjYF12aRVdwaiTmALx5XDfguQ9MnYtK
Views: 16210 Keifer Kif
This Is How Bitcoin Transactions Work
 
03:42
What I’m going to do now is show you how a Bitcoin transaction works. Now most transactions work in a similar way whether you’re buying, receiving and so on. So lets jump into showing you how it all works now, so you understand the process. // VIDEO TAKEN FROM // View: https://www.udemy.com/bitcoin-for-beginners/?couponCode=YOUTUBE10 // FREE BITCOIN WEBINAR // Join: http://bit.ly/2AR6v2v // CRYPTOCURRENCY & BLOCKCHAIN TUTORIALS // Sign-Up: https://www.b21block.com // FOLLOW US ONLINE // Subscribe: https://youtube.com/c/RavinderDeolB21Block?sub_confirmation=1 Like: https://facebook.com/B21Block
40% Bitcoin Price Crashes 📉 / Schnorr Signatures, The Next Big Upgrade The Bitcoin Core Code
 
15:42
Story - 40% Bitcoin Price Corrections 0:54 https://twitter.com/chrisconeyint/status/908661209184002048 Shout out to Twitter user Igor Ybema for reminding me of this tweet that I posted on the 15th of September. If we click on the image to zoom in we see the Bitcoin price running up 1826 to $5,000. Then within a couple of weeks it drops from $5,000 to $3,000. That was a 40% correction. For the benefit of the podcast listeners, I also drew some arrows on the chart which pointed to the 40% drop with some text saying “1 year from now, this…will look like this.” and then there’s another arrow pointing to this relatively small price correction from a couple of months before. My intention was to give myself and everyone else some perspective. And low and behold, it didn’t take 1 year, it took 3 months because when we switch to the Bitcoin chart of today… https://www.coinigy.com/main/markets/BITF/BTC/USD We see a very similar pattern except at different price levels. This time we ran up from 5400 to 20,000 and then crashed 45% down to $11,000. And for those of you watching the video version, this white circle is the previous price crash that I featured in that tweet, it doesn’t even register as significantly. If this pattern were to continue, then one day we would have a run up to $1m and then a price correction to $550,000. Hypothetically that’s true but realistically I don’t think that will happen because by the time we reach a $1m Bitcoin, we’ll have a lot more liquidity which will reduce volatility. In the meantime though, we may get some interim booms and busts that follow this pattern that make the recent crash look equally insignificant. Story - Schnorr Signatures, The Next Big Upgrade The Bitcoin Core Code 4:32 https://medium.com/@SDWouters/why-schnorr-signatures-will-help-solve-2-of-bitcoins-biggest-problems-today-9b7718e7861c This comes from Mr Sam Wouters Medium blog. This guy is a speaker and Bitcoin Consultant. As we all probably know by now there are 2 distinct camps in the Bitcoin community that have opposite ideas about how to increase the capacity of Bitcoin so it can process more transactions. The Bitcoin Cash community favor an approach that requires more computing resources but is simpler, while the Bitcoin community favor a creative approach where new techniques are invented to achieve more and more with the same resources. When the Bitcoin Cash community criticise Segwit, the main objection is that Segwit doesn’t improve scaling. That is true because Segwit was never meant to be a scaling solution. It doesn’t increase capacity slightly but that’s not it’s primarily purpose. Activating Segwit was a step of preparation to lay the foundations for many other technologies to build on. Now that we have Segwit, the road for those additional technologies is clear. One of those technologies is something called Schnorr signatures. As far as I understand it, Segwit is a prerequisite to use Schnorr Signatures. That means the code cannot be easily integrated into Bitcoin Cash in its current form. In a nutshell Schnorr Signatures as the name suggest, is a new way of handling how transactions are signed so that the signatures use up less storage space, and thus allow more transactions to fit inside a block. And to put that into perspective, we are looking at a 25% reduction in storage and bandwidth. This is accomplished basically by having all transactions just have 1 single signature, no matter how many addresses are involved. [see Today’s Signatures Image and Schnorr Signatures Image] But that’s not all, says Sam. Another big benefit of this increased efficiency from Schnorr signatures is a reduction in the effect of spam transactions. If we scroll back up to those diagrams, you can see that if I wanted to spam the Bitcoin network, I could intentionally send dozens of transactions and make sure they involved dozens or even hundreds of different addresses. The size of those transactions would mean the block space would get full without requiring a huge number of transactions. With schnorr signatures it greatly levels the playing field since those spam transactions would be on a level with legitimate transactions, each having to pay for only as much space as a single signature requires. As Sam points out here, the signature is often the part of the transaction that takes up the most space in a block. Schnorr signatures don’t prevent spam, they would just make them less disruptive to the regular users. While this all sounds very exciting, the major thing holding it back is the actual adoption of Segwit. http://segwit.party/charts/ Segwit was a backwards compatible soft fork, meaning Bitcoin can flow in and out of Segwit and non-Segwit addresses freely. And as we can see from Segwit Party, still only around 10% of all Bitcoin transactions are using Segwit addresses.
Views: 6874 The Cryptoverse