ezyang’s blog

the arc of software bends towards understanding


A Zerocoin puzzle

I very rarely post linkspam, but given that I’ve written on the subject of anonymizing Bitcoins in the past, this link seems relevant: Zerocoin: making Bitcoin anonymous. Their essential innovation is to have a continuously operating mixing pool built into the block chain itself; they pull this off using zero-knowledge proofs. Nifty! Here is a […]

  • April 11, 2013

Secure multiparty Bitcoin anonymization

Abstract. We describe how secure multi-party sorting can serve as the basis for a Bitcoin anonymization protocol which improves over current centralized “mixing” designs. Bitcoin is a pseudonymous protocol: while Bitcoin addresses are in principle completely anonymous, all traffic into and out of a wallet is publicly visible. With some simple network analysis collections of […]

  • July 20, 2012

The Cryptography of Bitcoin

It is actually surprisingly difficult for a layperson to find out precisely what cryptography Bitcoin uses, without consulting the source of Bitcoin directly. For example, the opcode OP_CHECKSIG, ostensibly checks the signature of something... but there is no indication what kind of signature it checks! (What are opcodes in Bitcoin? Well it turns out that […]

  • June 3, 2011