"Here’s an example to give you an idea of what it would take to get a SHA-1 collision. If all 6.5 billion humans on Earth were programming, and every second, each one was producing code that was the equivalent of the entire Linux kernel history (6.5 million Git objects) and pushing it into one enormous Git repository, it would take roughly 2 years until that repository contained enough objects to have a 50% probability of a single SHA-1 object collision. Thus, an organic SHA-1 collision is less likely than every member of your programming team being attacked and killed by wolves in unrelated incidents on the same night."
Deliberate collisions are addressed in the following paragraph.
SHA-1 hashes are not random, so the issue of poor pseudo-random number generation doesn't apply as it does to uuidv4. And SHA-1 hashes are 160 bits, vs. 128 for uuidv4.
<https://git-scm.com/book/en/v2>
"Here’s an example to give you an idea of what it would take to get a SHA-1 collision. If all 6.5 billion humans on Earth were programming, and every second, each one was producing code that was the equivalent of the entire Linux kernel history (6.5 million Git objects) and pushing it into one enormous Git repository, it would take roughly 2 years until that repository contained enough objects to have a 50% probability of a single SHA-1 object collision. Thus, an organic SHA-1 collision is less likely than every member of your programming team being attacked and killed by wolves in unrelated incidents on the same night."
Deliberate collisions are addressed in the following paragraph.
SHA-1 hashes are not random, so the issue of poor pseudo-random number generation doesn't apply as it does to uuidv4. And SHA-1 hashes are 160 bits, vs. 128 for uuidv4.
But I love the idea of unrelated wolf attacks.