4 ms·
> seed = SHA256(seed + "reseed") may have fixed points, or short cycles. If it does, doesn't that mean it's flawed as a cryptographic hash?
by zeveb 11y ago
> seed = SHA256(seed + "reseed") may have fixed points, or short cycles.
If it does, doesn't that mean it's flawed as a cryptographic hash?
- ucho 11y agoNo, it is a property of all hash functions - if you reduce input of arbitrary length to few bytes there will always be short circles. It is why you should always think twice before feeding output from one hash function call to another as the set of possible output values might be smaller and smaller with every repetition.