- From: Manu Sporny <msporny@digitalbazaar.com>
- Date: Tue, 1 Jan 2019 16:47:11 -0500
- To: daniel.hardman@evernym.com
- Cc: W3C Credentials CG <public-credentials@w3.org>
On 1/1/19 3:34 PM, Daniel Hardman wrote: > Sites like virustotal.com <http://virustotal.com> deal in hashes > constantly. They distinguish algorithms for hashes based on the > output size (MD5 has one size digest, SHA2 has another size, SHA256 > another size, etc). > > I assume we feel like adding a prefix is important because this > technique is not adequate? Yes, correct, because... MD5, SHAKE-128, blake2b-128, and blake2s-128 all have the same output sizes. SHA2 has 3 output sizes with two of them conflicting (SHA2-256 and double-SHA2-256). SHA3 has 4 output sizes, two of them conflicting w/ SHA2, Blake, and Shake. In other words, output size alone isn't enough. -- manu -- Manu Sporny (skype: msporny, twitter: manusporny, G+: +Manu Sporny) Founder/CEO - Digital Bazaar, Inc. blog: Veres One Decentralized Identifier Blockchain Launches https://tinyurl.com/veres-one-launches
Received on Tuesday, 1 January 2019 21:47:38 UTC