A cryptographic hash function
H can be used for encryption though, by mimicking a one-time pad: Pick a random integer
k, concatenate it with a secret
s, hash the result obtaining
H(s•k), XOR this with the plaintext yielding the ciphertext
C and send the pair (
k,
C). Pick another integer if you need to encrypt more data.
Decryption proceeds in the same way, mutatis mutandis. This is the basic idea behind one of the best currently used ciphers, ChaCha20: It builds on a hash function.
From a regulatory and legal perspective, this means that if you want to ban strong encryption, you must ban cryptographic hash functions.
Decryption proceeds in the same way, mutatis mutandis. This is the basic idea behind one of the best currently used ciphers, ChaCha20: It builds on a hash function.
From a regulatory and legal perspective, this means that if you want to ban strong encryption, you must ban cryptographic hash functions.