{"action":"created","issue":{"url":"https://api.github.com/repos/Electric-Coin-Company/zcash/issues/700","labels_url":"https://api.github.com/repos/Electric-Coin-Company/zcash/issues/700/labels{/name}","comments_url":"https://api.github.com/repos/Electric-Coin-Company/zcash/issues/700/comments","events_url":"https://api.github.com/repos/Electric-Coin-Company/zcash/issues/700/events","html_url":"https://github.com/Electric-Coin-Company/zcash/issues/700","id":130002007,"number":700,"title":"Protocol spec: document handling of zero-value coin input slots","user":{"login":"daira","id":643204,"avatar_url":"https://avatars.githubusercontent.com/u/643204?v=3","gravatar_id":"","url":"https://api.github.com/users/daira","html_url":"https://github.com/daira","followers_url":"https://api.github.com/users/daira/followers","following_url":"https://api.github.com/users/daira/following{/other_user}","gists_url":"https://api.github.com/users/daira/gists{/gist_id}","starred_url":"https://api.github.com/users/daira/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/daira/subscriptions","organizations_url":"https://api.github.com/users/daira/orgs","repos_url":"https://api.github.com/users/daira/repos","events_url":"https://api.github.com/users/daira/events{/privacy}","received_events_url":"https://api.github.com/users/daira/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/Electric-Coin-Company/zcash/labels/documentation","name":"documentation","color":"906b75"},{"url":"https://api.github.com/repos/Electric-Coin-Company/zcash/labels/libzerocash","name":"libzerocash","color":"f7b6c7"},{"url":"https://api.github.com/repos/Electric-Coin-Company/zcash/labels/needs%20prioritization","name":"needs prioritization","color":"d8ff04"},{"url":"https://api.github.com/repos/Electric-Coin-Company/zcash/labels/SECURITY","name":"SECURITY","color":"e01010"},{"url":"https://api.github.com/repos/Electric-Coin-Company/zcash/labels/zkSNARK%20circuit","name":"zkSNARK circuit","color":"ff5b55"}],"state":"open","locked":false,"assignee":{"login":"ebfull","id":3794471,"avatar_url":"https://avatars.githubusercontent.com/u/3794471?v=3","gravatar_id":"","url":"https://api.github.com/users/ebfull","html_url":"https://github.com/ebfull","followers_url":"https://api.github.com/users/ebfull/followers","following_url":"https://api.github.com/users/ebfull/following{/other_user}","gists_url":"https://api.github.com/users/ebfull/gists{/gist_id}","starred_url":"https://api.github.com/users/ebfull/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ebfull/subscriptions","organizations_url":"https://api.github.com/users/ebfull/orgs","repos_url":"https://api.github.com/users/ebfull/repos","events_url":"https://api.github.com/users/ebfull/events{/privacy}","received_events_url":"https://api.github.com/users/ebfull/received_events","type":"User","site_admin":false},"milestone":null,"comments":2,"created_at":"2016-01-30T15:53:08Z","updated_at":"2016-01-31T23:57:05Z","closed_at":null,"body":"This is an important security-critical change to the circuit and protocol. If we get the details wrong then it could allow attacks that violate balance or (less seriously, but still contrary to the intent) allow distinguishing transactions with different numbers of real input coins.\r\n\r\nThe circuit change was implemented in https://github.com/Electric-Coin-Company/libzerocash/commit/ab777baa700cdc5069336eef86ecdf58cace4a43 , but I'm still not totally clear on some of the details &mdash; for example, precisely which checks are disabled when v<sup>old</sup><sub>i</sub> is zero.\r\n\r\n@ebfull, can you write something for the Pour Proof section of the protocol spec about this, or explain it precisely enough for me to write that?"},"comment":{"url":"https://api.github.com/repos/Electric-Coin-Company/zcash/issues/comments/177663549","html_url":"https://github.com/Electric-Coin-Company/zcash/issues/700#issuecomment-177663549","issue_url":"https://api.github.com/repos/Electric-Coin-Company/zcash/issues/700","id":177663549,"user":{"login":"ebfull","id":3794471,"avatar_url":"https://avatars.githubusercontent.com/u/3794471?v=3","gravatar_id":"","url":"https://api.github.com/users/ebfull","html_url":"https://github.com/ebfull","followers_url":"https://api.github.com/users/ebfull/followers","following_url":"https://api.github.com/users/ebfull/following{/other_user}","gists_url":"https://api.github.com/users/ebfull/gists{/gist_id}","starred_url":"https://api.github.com/users/ebfull/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ebfull/subscriptions","organizations_url":"https://api.github.com/users/ebfull/orgs","repos_url":"https://api.github.com/users/ebfull/repos","events_url":"https://api.github.com/users/ebfull/events{/privacy}","received_events_url":"https://api.github.com/users/ebfull/received_events","type":"User","site_admin":false},"created_at":"2016-01-31T23:57:05Z","updated_at":"2016-01-31T23:57:05Z","body":"I don't think things like linear combinations and so on are necessary for the protocol spec."}}