Author: Joseph Poon 2016-08-09 19:28:14
Published on: 2016-08-09T19:28:14+00:00
In an email exchange between Rusty Russell and Joseph Poon, the pair discuss obscuring funding transactions. Russell suggests sending the "steal" transaction to the observer every time there is an update, which can be encrypted and hashed with the txid of the commit tx or the SHA256() of the signature on the commit tx. Russell also suggests using a txid qualifier and SHA256(txid) as the encryption key to avoid weakening the funding tx's obscurity. However, Poon points out that it may be necessary to identify when the transaction occurs as an index for outsourcing services, so the key cannot be directly derived from the txid with a single HMAC/sha256. He suggests two options: taking the txid and using two salts or HMACing the transaction itself (not txid) as the secret key. Poon favors encrypting the outsourcing blobs as this approach gives maximum flexibility in terms of implementation.
Updated on: 2023-05-24T00:13:57.290958+00:00