Re: [boost] [hash2] Question about cryptographic guarantees of hash_append_unordered_range

Vinnie Falco wrote:

On Sun, Dec 8, 2024 at 11:27 AM Ivan Matek via Boost wrote:

...

...sum is commutative.

Bitwise XOR and modular unsigned multiplication are also commutative.

Bitwise xor has the problem that xoring two equal values yields 0, so the sequences [1], [1, 1, 1], [1, 2, 2] and so on all hash to the same thing. Multiply has the problem that a single 0 cancels out everything, and the problem that multiplying 64 even numbers zeroes out the low 64 bits.