4 ms·
Ask HN: SHA2 vulnerability post was removed. Why? Is it legit?
Hello. A moment ago someone posted this: https://github.com/laie/WorldsFirstSha2Vulnerability
It's now gone from HN.
Is the vulnerability legit?
- deleted 9y ago[deleted]
- lisper 9y agoYes. It's legit. No idea why it was removed. It was actually deleted, not just flagged to death. [UPDATE] Turns out I was wrong and this is not a vulnerability at all: https://crypto.stackexchange.com/questions/48580/fixed-point-of-the-sha-256-compression-function https://crypto.stackexchange.com/questions/48580/fixed-point...
- jstanley 9y agoI cloned the repo in case it gets taken down from GitHub as well. It's also in ipfs at /ipfs/QmXZwBkdVXBQoB7uZMUh5bzfKAHXnJT836GV1xotiQ46RW and I've pinned it on both of my ipfs servers. If you want to do the same: ipfs pin add QmXZwBkdVXBQoB7uZMUh5bzfKAHXnJT836GV1xotiQ46RW or to get it from github: git clone https://github.com/laie/WorldsFirstSha2Vulnerability ipfs add -Hr WorldsFirstSha2Vulnerability/ (-H includes hidden files - i.e. .git/)
- deleted 9y ago[deleted]
- deleted 9y ago[deleted]
- ctz 9y agoA fixed point in the compression function is not a vulnerability. Not sure why the post was deleted though.
- dddddaviddddd 9y agoSee also https://news.ycombinator.com/item?id=14654696 https://news.ycombinator.com/item?id=14654696 where it's been reposted with comments.
- 8draco8 9y agoNew thread here https://news.ycombinator.com/item?id=14655077 https://news.ycombinator.com/item?id=14655077
- user5994461 9y agohttps://github.com/laie/WorldsFirstSha2Vulnerability https://github.com/laie/WorldsFirstSha2Vulnerability Work by a random dude who pretends to find infinite collision so bad that he can't publish it. No math. No explanation. The code is a mix of single letter variables with hardly any comment. Thank you, I'll pass.
- jstanley 9y agoThe code sets up a sha256 state, then adds some input to sha256, and then demonstrates that the sha256 state is the same as it was. I'd say that counts as a vulnerability. It doesn't mean sha256 is broken, but it's a vulnerability. EDIT: All of this modulo a rigged sha256.py, of course
- user5994461 9y agoYou can google for existing sha256 collisions, nothing special in hard coding one. Google it and you'll find the source, if it's a popular collision already published in papers.
- lisper 9y agoI think you're confusing SHA256 with SHA1.
- lisper 9y agoYes, but the rigged sha256 seems to produce the same results as a real sha256. And there's nothing obviously hinky in the code that I can see on cursory inspection. If this is rigged, it's rigged in a particularly clever way. [UPDATE] Turns out this is not a vulnerability at all: https://crypto.stackexchange.com/questions/48580/fixed-point-of-the-sha-256-compression-function https://crypto.stackexchange.com/questions/48580/fixed-point...