There is a file
A and a file
If I have only
HASH(B) are there any non-trivial hash functions for which I could calculate both
HASH(A ++ B) and
HASH(B ++ A) without knowing A and B?
Can this be extended further?
Are there hash functions where, if I know HASH(A ++ B) and HASH(B), I can find HASH(A)?
(By trivial, I mean XOR, etc. "++" is the concatenation operator.)
Are any of these functions "good"? i.e. they have a low chance of collisions for non-malicious data.
Are any of these hash functions cryptographically secure?