639
The White House wants to 'cryptographically verify' videos of Joe Biden so viewers don't mistake them for AI deepfakes
(www.businessinsider.com)
this post was submitted on 11 Feb 2024
639 points (97.9% liked)
Technology
59429 readers
3110 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
Most hash functions are 256 bit (they're symmetric functions, they don't need more in most cases).
There are arbitrary length functions (called XOF instead of hash) which built similarly (used when you need to generate longer random looking outputs).
Other than that, yeah, math shows you don't need to change more data in the file than the length of the hash function internal state or output length (whichever is less) to create a collision. The reason they're still secure is because it's still extremely difficult to reverse the function or bruteforce 2^256 possible inputs.
Yeah I was using a high length at first because even if you overestimate, that's still a lot. I did 512 for the second because I don't know a ton about cryptography but that's the largest SHA output