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by dgrin91 2064 days ago
How is reversing the hash of an IP easy? Are you saying because there are only 4billion ipv4s? Hash should be fine for ipv6 still, right?
2 comments

Well hashing is (usually) a symmetric function and we are open source... Meaning you could recover the key in the code (or intercept it during transfer). I think Private/Public key is a simpler approach, reusable elsewhere in the code and it's known to be safe. But I'm not the CTO either, I could be mistaken.
Hashes aren't symmetric and don't use a key.
Here, I found this really useful to understand hashes: https://crackstation.net/hashing-security.htm
(but I think they already send it through HTTPS)
But would you want to only block single IPv6 addresses? Usually whole blocks are assigned as far as I know? So just hashing a single ipv6 would probably not work very well.