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Diffstat (limited to 'python/PyECC/ecc/shacrypt.py')
| -rw-r--r-- | python/PyECC/ecc/shacrypt.py | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/python/PyECC/ecc/shacrypt.py b/python/PyECC/ecc/shacrypt.py new file mode 100644 index 000000000..69ee7b943 --- /dev/null +++ b/python/PyECC/ecc/shacrypt.py @@ -0,0 +1,38 @@ +# ------------------------------------------------------------------------------ +# +# SHA-512-BASED FEISTEL CIPHER +# by Toni Mattis +# +# Feistel Function: SHA-512(Block || Key) +# Key Size: Fully Dynamic +# Block Size: 1024 Bits +# Rounds: User-Specified +# +# ------------------------------------------------------------------------------ + +from hashlib import sha512 + +BPOS = tuple(range(64)) + +def enc_block(block, key, rounds = 16): + x = block[:64] + y = block[64:] + for i in xrange(rounds): + h = sha512(x + key).digest() + y = ''.join([chr(ord(y[k]) ^ ord(h[k])) for k in BPOS]) + h = sha512(y + key).digest() + x = ''.join([chr(ord(x[k]) ^ ord(h[k])) for k in BPOS]) + return x + y + +def dec_block(block, key, rounds = 16): + x = block[:64] + y = block[64:] + for i in xrange(rounds): + h = sha512(y + key).digest() + x = ''.join([chr(ord(x[k]) ^ ord(h[k])) for k in BPOS]) + h = sha512(x + key).digest() + y = ''.join([chr(ord(y[k]) ^ ord(h[k])) for k in BPOS]) + return x + y + + + |