Aug 10, 2016Re-Imagining Cold Storage with TimelocksCold storage is a technique to keep keys offline and inaccessible to attackers. It is used by most major Bitcoin exchanges, occasionally moving funds between a “hot” wallet (used to satisfy user withdrawals) and an offline “cold” wallet. Exchanges then infrequently move Bitcoin between the two as demand changes. Cold…Bitcoin10 min readBitcoin10 min read
Jun 14, 2016What’s Wrong with Proof of Stake?Using computers to manage assets is not new. Indeed that’s a major reason computers were invented. What, then, makes Bitcoin and blockchains different? All digital financial assets before Bitcoin can be called IOU systems. The systems and databases themselves do not hold assets. The records in the database are an…Bitcoin9 min readBitcoin9 min read
May 17, 2016Blockchain Proof of LocationAn event (defined by the hash H) can be constrained to exist within a time window A < t < B by hashing H with the most recent block hash A in a blockchain, and incorporating them both into the next block B=hash(H,A,nonce). Bitcoin’s proof-of-work algorithm also has a nonce…Bitcoin6 min readBitcoin6 min read
May 11, 2016Is Bitcoin’s Proof of Work Useless Work?Charlie Brummitt asked me an interesting question the other day: “can bitcoin mining be changed so that the computations could simultaneously be used for science (e.g., protein folding, SETI)?” A common complaint about Bitcoin is that it uses a lot of energy, especially among people who first encounter it —…Bitcoin5 min readBitcoin5 min read
Apr 26, 2016Three Challenges for Scaling BitcoinThe most savage controversies are those about matters as to which there is no good evidence either way. - Bertrand Russell Bitcoin has come a long way in seven+ years. Being open source software, it lends itself to communal comments and debate. And while we are confident that scaling the…Bitcoin7 min readBitcoin7 min read
Apr 19, 2016Go Fork Yourself (to More Bitcoin Transactions)What is Bitcoin? There are two good, possible answers: Bitcoin is whatever is contained in the longest sha256 proof-of-work chain Bitcoin is the set of transactions deemed to be valid by the reference implementation of Bitcoin. As with all great arguments demanding of blood and tears, the source of the…Bitcoin9 min readBitcoin9 min read
Apr 6, 2016Bring Science to BitcoinBitcoin and crypto-currency is a nascent field. There are a lot of new, un-vetted ideas floating about. This field really got kicked off by an pseudonymous person placing a whitepaper and a pile of code on the internet. Due to the nature of Satoshi’s contribution, this mechanism of communication was…Bitcoin3 min readBitcoin3 min read
