Cryptographic hash functions with mathematical properties and practical implementations. Mathematical Definition A cryptographic hash function $H: {0,1}^* \to {0,1}^n$ maps arbitrary-length input to fixed-length output. $$ H(m) = h $$ Where: $m$: Message (arbitrary length) $h$: Hash digest (fixed length, e.g., 256 …

Hash and digitally sign text using public/private key pairs. Hash Text (OpenSSL) 1# SHA-256 hash 2echo -n "Hello, World!" | openssl dgst -sha256 3echo -n "Hello, World!" | openssl sha256 4 5# SHA-512 hash 6echo -n "Hello, World!" | openssl dgst -sha512 7 8# Hash file 9openssl dgst -sha256 …