I am happy to announce the first successful Zero-Knowledge Contingent Payment (ZKCP) on the Bitcoin network.
ZKCP is a transaction protocol that allows a buyer to purchase information from a seller using Bitcoin in a manner which is private, scalable, secure, and which doesn’t require trusting anyone: the expected information is transferred if and only if the payment is made. The buyer and seller do not need to trust each other or depend on arbitration by a third party. Imagine a movie-style “briefcase swap” (one party with a briefcase full of cash, another containing secret documents), but without the potential scenario of one of the cases being filled with shredded newspaper and the resulting exciting chase scene. An example application would be the owners of a particular make of e-book reader cooperating to purchase the DRM master keys from a failing manufacturer, so that they could load their own documents on their readers after the vendor’s servers go offline. This type of sale is inherently irreversible, potentially crosses multiple jurisdictions, and involves parties whose financial stability is uncertain–meaning that both parties either take a great deal of risk or have to make difficult arrangement. Using a ZKCP avoids the significant transactional costs involved in a sale which can otherwise easily go wrong. In today’s transaction I purchased a solution to a 16x16 Sudoku puzzle for 0.10 BTC from Sean Bowe, a member of the Zcash team, as part of a demonstration performed live at Financial Cryptography 2016 in Barbados. I played my part in the transaction remotely from California. The transfer involved two transactions: 8e5df5f792ac4e98cca87f10aba7947337684a5a0a7333ab897fb9c9d616ba9e 200554139d1e3fe6e499f6ffb0b6e01e706eb8c897293a7f6a26d25e39623fae Almost all of the engineering work behind this ZKCP implementation was done by Sean Bowe, with support from Pieter Wuille, myself, and Madars Virza. Read more, including technical details at https://bitcoincore.org/en/2016/02/26/zero-knowledge-contingent-payments-announcement/ [I hope to have a ZKCP sudoku buying faucet up shortly. :) ] _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
