311–320 of 369 posts
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Squeamish Osssifrage's answer to this Crypto Stack Exchange question does a predictably excellent job of putting these attacks in context. https://crypto.stackexchange.com/questions/60640/does-shatte...
Agreed. It's a great loss to the community that they have decided to step away from Stack Exchange: https://crypto.meta.stackexchange.com/questions/1361/im-leav...
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Encrypting is still better than not encrypting and if you care about keeping your data private then you can take additional measures to ensure that. Nothing will last forever but that's not a good reason to be nihilistic.
It's like locking my front door. I chose to lock the door to prevent random acts of burglary. But that lock will not stop someone determined from BnE my house.
They might BnE your key though, if you aren't careful enough.
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Relatedly, that is a part of why I love the term "cryptoarcheology" in general, as a reminder that digital spaces will need archeologists too. There's it's somewhat shortened form "cryptarch", generally more used as a title ("cryptoarcheologist"), which was used in places in the Quantum Thief trilogy of books and is most probably already burned into your brain if you have played any of the Destiny series of videogame…
Hmm, I thought cryptarch was just crypt + arch with the arch part meaning “leader” (i.e. this sense https://www.etymonline.com/word/arch- ), not archaeologist. Is there something about this in the Quantum Thief trilogy I’ve forgotten?
(I don't think Destiny does much with the playful dual meaning, though. Certainly the cryptarchs in Destiny have never yet been meaningful leaders.)
This kind of thing always brings me down a bit. It's not rational, but it does. I mean I truly admire these folks skills, the math involved is obviously remarkable. But I think the feeling is related to not being able to rely on anything in our field. Hard to justify going to the trouble of encrypting your backup. 10 years from now, it might be as good as plain text. It's not security only, nothing seems to work in t…
There's an MC Frontalot song called "Secrets from the Future" and the refrain is "You can't hide secrets from the future." It's something of a useful mantra to remind oneself that if "the future" is a part of your threat model, yes your encryption likely isn't enough because on a long enough timescale it is likely "the future" will crack it. As with any other security issue, the question is "what is your threat model…
With the usual disclaimer about one-time pads.
> other fun forms of entropy beyond encryption being cracked such as encodings changing, file formats falling out of service/compatibility, "common knowledge" about slang or memes lost to the ages leaving things indecipherable
I wonder what the digital archaeologists of the future will make of today's programming languages.
(I was going to point out how far we've come since the languages of yesteryear, but we still have such horror-shows as Perl and Bash.)
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I was wondering the same thing, and hoping someone else would answer that.
Hardened sha1 does detect this new attack. Easy to test: Check their pair of files into a git repo and see that they have different checksums, while sha1sum(1) generates the same for both.
$ mkdir sha1
$ cd sha1
$ curl -O https://sha-mbles.github.io/messageA
...
$ curl -O https://sha-mbles.github.io/messageB
...
$ echo foo > bar
$ echo foo > baz
$ openssl sha1 *
SHA1(bar)= f1d2d2f924e986ac86fdf7b36c94bcdf32beec15
SHA1(baz)= f1d2d2f924e986ac86fdf7b36c94bcdf32beec15
SHA1(messageA)= 8ac60ba76f1999a1ab70223f225aefdc78d4ddc0
SHA1(messageB)= 8ac60ba76f1999a1ab70223f225aefdc78d4ddc0
$ git init
Initialized empty Git repository in ...
$ git add *
$ git commit
[master (root-commit) b274c88] sha1 collision test
...
4 files changed, 2 insertions(+)
create mode 100644 bar
create mode 100644 baz
create mode 100644 messageA
create mode 100644 messageB
$ git ls-files -s *
100644 257cc5642cb1a054f08cc83f2d943e56fd3ebe99 0 bar
100644 257cc5642cb1a054f08cc83f2d943e56fd3ebe99 0 baz
100644 5a7c30e97646c66422abe0a9793a5fcb9f1cf8d6 0 messageA
100644 fe39178400a7ebeedca8ccfd0f3a64ceecdb9cda 0 messageB
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Cryptographers rely on precise definitions to make their assessments. In particular, a primitive makes a number of useful promises. Any achievement that describes a way in which a promise is not kept makes that primitive broken , regardless of whether that achievement is theoretical or practical. (They often talk about “theoretically broken” or “practically broken” to distinguish whether it was actually done.) > it's…
Is SHA1 not still faster than 256/512? And Blake2 barely faster? I suspect with some hardware SHA1 is still going to beat all of those out - am I wrong? I would love to learn more.
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This biblical prophecy from Luke 12,3 is solo true: " What you have said in the dark will be heard in the daylight, and what you have whispered in the ear in the inner rooms will be proclaimed from the roofs."
I wonder what the intended meaning is. I presume it has to do with a presumed eventual urge to confess.
Q: Does this make it even more urgent for git to move to a different hash?
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I'm not sure what that sentence means, can you rephrase it?
The analysis you have provided for why SHA-512 is superior to SHA-256 is faulty.
Pity it didn't come across that way.