Linus' reply on Git and SHA-1 collision

Re:Linus' reply on Git and SHA-1 collision by hannob on Friday February 24, 2017 @05:04AM (#13722423)

The Git docs have some very specific claims about cryptographic integrity of git:

https://git-scm.com/about/info-assurance

These claims are wrong as long as it uses SHA-1. Full stop.

It'd be really nice if git had cryptographic integrity. Not just because it'd prevent some attacks on git repos, but because it'd make git essentially a secure append only log. Which would be interesting, as it'd more or less automatically give some kind of software transparency for many projects.

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Re:Linus' reply on Git and SHA-1 collision by dromen on Friday February 24, 2017 @06:10AM (#13722645)

Some more advanced Git operations (I sadly never needed so far) can be used to break the "append only" part, right?

Like for instance rebases?

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Re:Linus' reply on Git and SHA-1 collision by hannob on Friday February 24, 2017 @06:11AM (#13722647)

You can always break append only logs, the point is, it's detectable.

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Re:Linus' reply on Git and SHA-1 collision by dromen on Friday February 24, 2017 @10:43AM (#13724627)

What do you mean by detectable in the context of Git-as-append-only-log?

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Re:Linus' reply on Git and SHA-1 collision by azernik on Saturday February 25, 2017 @03:19PM (#13733612)

Mirrors that pull down the version with rewritten history will not be able to run a fast-forward (because they will contain commits that are not in the upstream version), and will loudly complain.

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