From: Hans Petter Selasky <hps@selasky.org>
Date: Fri, 13 Jan 2023 16:02:23 GMT
Subject: Re: Gitorious should use CRC128 / 256 / 512 instead of SHA-1
Message-ID: <078526fc-7f2d-c745-a292-ff78dc06e407@selasky.org>
In-Reply-To: <00b201d92767$a0403ee0$e0c0bca0$@nexbridge.com>

On 1/13/23 16:56, rsbecker@nexbridge.com wrote:
> git is using SHA1/SHA256 (which happen to be coincidentally cryptographic) as message digests with a very low probability of collisions when the hashes are computed. There is never a situation, implied by cryptography, where there is a decode of a git hash.  In order to make git a blockchain, you would need to implement central signing authorities, which would require a fork if the signature mechanism changes. The signature mechanism (SSH, GPG) is distinct from hash computation in git's trees, but depends on hash integrity.

I see.

But at the same time any unique enough hash, identifies a specific piece 
of code or checkout, even though it is not under a specific signing 
authority. And that is the problem, that authorities may distribute 
allowed-only-hashes for their hardware ...

--HPS