Bitcoin Q&A: How do payment channels work?

Bitcoin Q&A: How do payment channels work?

“Can you explain the Lightning Network and how payment channels with ‘locked’ funds work?” Yes. Let’s start with payment channels. Payment channels are [opened from]… transactions on the Bitcoin network that lock funds in a 2-of-2 multi-signature address. If I have a payment channel with Alice, that has [bitcoin] locked [in a multi-sig with one key from each of us]. I commit an [amount] of funds to the balance of…

Understand how bitcoin works in just over 3 minutes | Elevator Pitch

Do you know what blockchain is? Not really. Do you know what Bitcoin is? Sort of. It’s digital money that people use computers to mine and it’s worth heaps and it’s really unstable and it might be the way of the future and I think bitcoins are made with blockchain. Err.. I’m going to ask a computer scientist to break it down for me in a time it takes an…

Ethereum Q&A: Why I’m writing ‘Mastering Ethereum’

“People are worrying that they’re going to lose you, Andreas, to the altcoin sphere.” Oh no! “Peter says, “Recently I’ve seen more and more people, especially on Twitter, commenting on… whether you will remain faithful to Bitcoin.” “In certain ways, I empathise. You certainly have never been in this for the money.” “That’s what I truly and thoroughly believe.” “It makes me wonder why you would spend so much time…

Ethereum Q&A: Smart contract platforms

Ethereum Q&A: Smart contract platforms

Q: “Which do you think is a superior platform for smart contracts? Bitcoin with side chains like Rootstock? Ethereum or one of the self-proclaimed 3G or third-generation blockchains?” I mean the problem is you can’t really compare these things, and the reason you can’t compare them is because one exists and the other two are mostly road map or test software at the moment. So, Ethereum exists, and you can…

Ethereum Q&A: Light clients, EVM, and Mist

Marcus asks, “Why would one use Metamask, MyEtherWallet, or MyCrypto?” “Is it just that they can hold multiple Ethereum-based tokens, or do they have more useful capabilities?” Metamask, MyEtherWallet, and MyCrypto are three lightweight clients and wallets. They don’t just implement wallet functionality. They make the Web3 Javascript interface available… in your browser, that allows applications (DApps) to run and access the Ethereum network. Through this wallet, [you can] create…

Bitcoin Q&A: What are “bitcoin days destroyed”?

Bitcoin Q&A: What are “bitcoin days destroyed”?

On “bitcoin days destroyed,” Grinners asks, “Bitcoin days destroyed is calculated by taking… the number of bitcoins multiplied by the number of days since those coins were last spent.”‘ “What is the significance of this? What does this actually tell us?” It gives us an idea of the maturity of coins, how often coins are moved and in what amounts. You can look at it this way: somebody moving one…

Ethereum Q&A: Smart contract platforms

Q: “Which do you think is a superior platform for smart contracts? Bitcoin with side chains like Rootstock? Ethereum or one of the self-proclaimed 3G or third-generation blockchains?” I mean the problem is you can’t really compare these things, and the reason you can’t compare them is because one exists and the other two are mostly road map or test software at the moment. So, Ethereum exists, and you can…

Ethereum Smart Contract Code Review #1 – Real World CTF 2018

Ethereum Smart Contract Code Review #1 – Real World CTF 2018

When the CTF started we looked at the challenges and I already suspected, just because it’sin-style right now, that there could be an ethereum smart contract challenge.And there was!Acoraida Monica.So I didn’t even look at the rest and just decided to go for it.In the end I didn’t solve the challenge during the two days of CTF, so in this firstvideo I want to tell you about my failed attempts,…

Attacks on Ethereum Smart Contracts

Attacks on Ethereum Smart Contracts

Hey everyone!This is David Wong, and in this video I will talk about attacks on Ethereum smart contracts.And I’m not making things up, I’m just giving you a tl;dr of this paper called“A survey of attacks on Ethereum smart contracts”.It’s written by Nicola Atzei, Massimo Bartoletti and Tizianna Cimoli from the university ofCagliari (Italy)So if you want more details, be sure to check their paper.Before I start showing off real…

Ethereum Q&A: “Blockchain all the things”

Ethereum Q&A: “Blockchain all the things”

“In the Internet of Things (IoT), it is important to make sure that we are connected to [the right devices].”“Do you think blockchains can help in solving IoT security issues?”“Do you know of any IoT solutions using blockchains to enforce security?”I am quite skeptical when it comes to blockchains being used for IoT security.One of the interesting ideas we haven’t explored is using proof-of-work to identify IoT devices…that must do…