For the tech community, our findings emphasize the necessity of sunsetting SHA-1 usage. Google has advocated the deprecation of SHA-1 for many years, particularly when it comes to signing TLS certificates. As early as 2014, the Chrome team announced that they would gradually phase out using SHA-1. We hope our practical attack on SHA-1 will cement that the protocol should no longer be considered secure.
NickMNS
5:46 pm on Feb 23, 2017 (gmt 0)
This is just crazy stuff, and I amnot sure what is more crazy the Math or the Computer Science.
Nine quintillion (9,223,372,036,854,775,808) SHA1 computations in total
Dimitri
10:12 pm on Feb 23, 2017 (gmt 0)
Some will certainly come and argue that this is #*$!, and that Google is pushing people to use other encryption algorithms to make more money...
robzilla
10:35 pm on Feb 23, 2017 (gmt 0)
Cryptography is a mind-boggling affair, and I'm glad other people bother with it so I don't have to :-)
graeme_p
6:03 am on Feb 24, 2017 (gmt 0)
@Dimitri - how would Google profit from this?
robzilla
10:52 am on Feb 24, 2017 (gmt 0)
They wouldn't, of course, but I think that's his point.
tangor
12:31 pm on Feb 24, 2017 (gmt 0)
More commentary
'First ever' SHA-1 hash collision calculated. All it took were five clever brains... and 6,610 years of processor time
However, it is not beyond the reach of a large corporation or intelligence agency to forge a TLS certificate, a Git repo...
Forge a GIT repo! There must be a few nervous tech companies around, wondering whether their code is safe? The door opened by this vulnerability is huge. One could steal the code outright. But far worse you could inject malware into the code without anyone ever knowing, steal customer data, spy on users, a Stuxnet type attack could be carried out without requiring physical contact with the computer (assuming code base for the attack is repoed on GIT).
Dimitri
2:34 pm on Feb 24, 2017 (gmt 0)
My comment was a joke, as a reference to the discussions held at the HTTPS topic :-)
tangor
4:43 pm on Feb 24, 2017 (gmt 0)
@Dimiri: Jokes are harder to perceive in these desperate daze! (sic)
robzilla
11:42 pm on Feb 24, 2017 (gmt 0)
FYI: WebmasterWorld has an intermediate certificate with a weak SHA-1 signature in its chain.
ergophobe
4:34 am on Feb 25, 2017 (gmt 0)
Uh Oh... Of course, for right now, probably not many people outside of Google and government actors can exploit that, but time to get the house in order.
robzilla
8:48 am on Feb 25, 2017 (gmt 0)
True, but browsers are expected to drop SHA-1 soon, so you might lose your padlock.
SHA-1 Defeated
