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Comment by bsuvc

5 days ago

Not impossible, just more difficult to guess.

"Security through obscurity" isn't really good enough.

Yes and…

UUIDs aren’t “just more difficult to guess.” They are inconceivably harder to guess.

> Put another way, one would need to generate 1 billion v4 UUIDs per second for 85 years to have a 50% chance of a single collision.

  • You are both right. UUIDs, if randomly generated from a CSPRNG are impossible to guess. But not all UUIDs are generated from a secure RNG, or use randomness at all.

Yes, you are technically right -- I should have said "functionally impossible". It's not actually impossible, but close enough for the average random onlooker.