Why wouldn't you be able to? Most file formats have ways of including comment da... | Hacker News

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		dheera on Feb 25, 2017 \| parent \| context \| favorite \| on: SHA-1 collider: Make your own colliding PDFs Why wouldn't you be able to? Most file formats have ways of including comment data, including JPEG, GIF, HTML, C code, and most others. You could potentially create a piece of noble C code and a piece of malicious C code that collide. (However, creating a piece of malicious code that matches an existing codebase that doesn't contain a comment would be hard, if I understand correctly.)

aidenn0 on Feb 25, 2017 [–]

This reuses the prefix that Google calculated, which is a PDF header. Therefore you can only generate PDFs with this technique.

If you want to dedicate a few hundred GPU-years to it, you could generate similar colliding prefixes for other formats by doing what Google did.

dheera on Feb 25, 2017 | [–]

Ah, I see, thanks.

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