MDC-2

From Wikipedia, the free encyclopedia

In cryptography, MDC-2 (Modification Detection Code 2, sometimes called Meyer-Schilling) is a cryptographic hash function with a 128-bit hash value. MDC-2 is a hash function based on a block cipher.

The U.S. Patent 4,908,861 , submitted by IBM, expires on August 28, 2007. For patent reasons, support for MDC-2 has been disabled in OpenSSL on most Linux distributions.

[edit] MDC-2 hashes

The 128-bit (16-byte) MDC-2 hashes are typically represented as 32-digit hexadecimal numbers. The following demonstrates a 43-byte ASCII input and the corresponding MDC-2 hash:

 MDC2("The quick brown fox jumps over the lazy dog") 
  = 000ed54e093d61679aefbeae05bfe33a

Even a small change in the message will (with probability) result in a completely different hash, e.g. changing d to c:

 MDC2("The quick brown fox jumps over the lazy cog") 
  = 775f59f8e51aec29c57ac6ab850d58e8

The hash of the zero-length string is:

 MDC2("") = 52525252525252522525252525252525

[edit] See also


Hash algorithms: Gost-Hash | HAS-160 | HAVAL | MDC-2 | MD2 | MD4 | MD5 | N-Hash | RIPEMD | SHA family | Snefru | Tiger | VEST | WHIRLPOOL | crypt(3) DES
MAC algorithms: Data Authentication Code | CBC-MAC | HMAC | OMAC/CMAC | PMAC | UMAC | Poly1305-AES | VEST
Authenticated encryption modes: CCM | EAX | GCM | OCB | VEST Attacks: Birthday attack | Collision attack | Preimage attack | Brute force attack
Standardization: CRYPTREC | NESSIE Misc: Avalanche effect | Hash collision | Hash functions based on block ciphers
Cryptography
v d e
History of cryptography | Cryptanalysis | Cryptography portal | Topics in cryptography
Symmetric-key algorithm | Block cipher | Stream cipher | Public-key cryptography | Cryptographic hash function | Message authentication code | Random numbers
In other languages