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Is a 30 day disclosure period really enough for something like this? It's obviously not possible to 'fix' big systems that rely on SHA-1 such as git or github in only 30 days. Hardware devices that use SHA-1 as a base for authenticating firmware updates?
Is this correct?
So good timing to have just started working on a sha3 version of git I guess...
Funny, just yesterday I thought about what would be necessary to change and deploy this. Apparently the SHA1 hash wasn't designed as a security feature, but I would not be surprised if it is being abused as one today.
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…
Creating a file with the same hash as legit file is a preimage attack and is much more difficult to perform (many orders of magnitude more difficult).
This still doesn't mean that SHA-1 isn't dogshit however. It should have been phased out years ago.
Earlier quoted context omitted.
EDIT: My original comment was wrong. Git commit signing apparently only signs the commit hash itself, so it's only as trustworthy as the integrity of the hash. However, see also other comments which point out that this isn't a pre-image attack; you can't find a collision for a given thing (in this case, the linux kernel); rather, you can generate from scratch two pieces of data which happen to collide. Still, this is…
>git has commit signing What the commit actually signs? Is it the sha1 hash?
Here's a good blog about how SHA-1 works: http://www.metamorphosite.com/one-way-hash-encryption-sha1-d... . The biggest risk I see with this is how torrents are affected: https://en.wikipedia.org/wiki/Torrent_poisoning There's also a problem with git, but I don't see it being that as susceptible as torrents: http://stackoverflow.com/a/34599081/6448137
>torrents Good, if something stronger and better comes out it'll still be a win.
I'm sure a BEP will also come up, and speedtracked on the back of this news.
>Nine quintillion computations; 6,500 years of CPU; 110 years of GPU Is there a rough calculation in terms of today's $$$ cost to implement the attack?
Say you want to replicate this in 1 month, you need 1320 GPUs for a month. They didn't specify which ones, but say at 1000 bucks per GPU, that's a 1.3M USD investment. And some pocket change for power etc. There isn't anything new about this result actually, Google just set aside the necessary resources to demonstrate it.
>Nine quintillion computations; 6,500 years of CPU; 110 years of GPU Is there a rough calculation in terms of today's $$$ cost to implement the attack?
Probably peanuts to any 3 letter government agency.
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…
None of what you mentioned is affected since this is a collision attack. They purposely created 2 files with the same hash. Creating a file with the same hash as legit file is a preimage attack and is much more difficult to perform (many orders of magnitude more difficult). This still doesn't mean that SHA-1 isn't dogshit however. It should have been phased out years ago.
Release one into the wild.
Wait.
Infect.
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…
None of what you mentioned is affected since this is a collision attack. They purposely created 2 files with the same hash. Creating a file with the same hash as legit file is a preimage attack and is much more difficult to perform (many orders of magnitude more difficult). This still doesn't mean that SHA-1 isn't dogshit however. It should have been phased out years ago.