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Pretty impressive, though. And worrying, because if Google can do it, you know that state-level actors have been probably doing it for some time now (if only by throwing even more computing power at the problem).
>Nine quintillion computations; 6,500 years of CPU; 110 years of GPU Is there a rough calculation in terms of today's $$$ cost to implement the attack?
There isn't anything new about this result actually, Google just set aside the necessary resources to demonstrate it.
* DHT/torrent hashes - A group of malicious peers could serve malware for a given hash.
* Git - A commit may be replaced by another without affecting the following commits.
* PGP/GPG -- Any old keys still in use. (New keys do not use SHA1.)
* Distribution software checksum. SHA1 is the most common digest provided (even MD5 for many).
Edit: Yes, I understand this is a collision attack. But yes, it's still a attack vector as 2 same blocks can be generated now, with one published, widely deployed (torrent/git), and then replaced at a later date.
No need to wait. The option to reject SHA-1 certificates on Firefox is `security.pki.sha1_enforcement_level` with value `1`.
https://blog.mozilla.org/security/2016/01/06/man-in-the-midd...
Other configs worth doing:
`security.ssl.treat_unsafe_negotiation_as_broken` to `true` and `security.ssl.require_safe_negotiation` to `true` also. Refusing insecure algorithms (`security.ssl3.`) might also be smart.
>Nine quintillion computations; 6,500 years of CPU; 110 years of GPU Is there a rough calculation in terms of today's $$$ cost to implement the attack?
Big things affected: * DHT/torrent hashes - A group of malicious peers could serve malware for a given hash. * Git - A commit may be replaced by another without affecting the following commits. * PGP/GPG -- Any old keys still in use. (New keys do not use SHA1.) * Distribution software checksum. SHA1 is the most common digest provided (even MD5 for many). Edit: Yes, I understand this is a collision attack. But yes, it…
What's the impact to something like git that makes extensive use of SHA-1? In their example they've created two PDFs with the same SHA-1. Could I replace the blob in a git repo with the "bad" version of a file if it matches the SHA-1?
There's a good explanation here: http://stackoverflow.com/a/34599081/6448137
edit.: they seem to quote 560k, I overlooked using both the CPUs and the GPUs.
What's the impact to something like git that makes extensive use of SHA-1? In their example they've created two PDFs with the same SHA-1. Could I replace the blob in a git repo with the "bad" version of a file if it matches the SHA-1?
tl;dr it's a non-issue