Author: Kalle Rosenbaum 2015-07-26 21:13:49
Published on: 2015-07-26T21:13:49+00:00
In an email thread discussing the size of the nonce used in Proof of Payment (PoP) as outlined in Bitcoin Improvement Proposal (BIP) 120, it was noted that Bitcoin core now supports 80 bytes of data by default and does not maintain a policy limit. The BIP had assumed a limit of 40 bytes across all implementations. It was suggested that if there is a need to increase the size of the nonce, it could be done in a subsequent version of PoP. However, a longer nonce would result in bigger QR codes generated from the BIP 121 URIs, making 48 bits a good tradeoff for now. It was also mentioned that a server generating PoP requests should try to detect brute force attacks or delay the response containing the nonce by some 100ms. If PoP becomes an extension of BIP70, then there will be no size constraint on the nonce.
Updated on: 2023-06-09T22:27:37.287837+00:00