Search:

The Bouncy Castle Crypto package seems to have Whirlpool digests. I don't know more.

Ok, this has sense! You have 128 hex digits, that means 64 bytes = 512 bits.
Similar to what I see in Whirlpool hashes.

Very in general, a byte[] obtained by any "hash" (or "digest") function is not something that is directly human-readable, because it contains raw bytes, that is, a sequence of bytes of any value in...