Panama is a cryptographic primitive which can be used both as a
hash function and a
stream cipher
stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream ...
, but its hash function mode of operation has been broken and is not suitable for cryptographic use. Based on
StepRightUp, it was designed by
Joan Daemen and Craig Clapp and presented in the paper ''Fast Hashing and Stream Encryption with PANAMA'' on the Fast Software Encryption (FSE) conference 1998. The cipher has influenced several other designs, for example
MUGI
In cryptography, MUGI is a pseudorandom number generator (PRNG) designed for use as a stream cipher. It was among the cryptographic techniques recommended for Japanese government use by CRYPTREC in 2003, however, has been dropped to "candidat ...
and
SHA-3.
[http://csrc.nist.gov/groups/ST/hash/sha-3/documents/Keccak-slides-at-NIST.pdf On slide 5, it states the "starting
point: fixing Panama"]
The primitive can be used both as a
hash function and a
stream cipher
stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream ...
. The stream cipher uses a 256-bit key and the performance of the cipher is very good reaching 2
cycles per byte.
Hash function
As a hash function, collisions have been shown by
Vincent Rijmen
Vincent Rijmen (; born 16 October 1970) is a Belgian cryptographer and one of the two designers of the Rijndael, the Advanced Encryption Standard. Rijmen is also the co-designer of the WHIRLPOOL cryptographic hash function, and the block cip ...
et al. in the paper ''Producing Collisions for PANAMA'' presented at FSE 2001. The attack shows a
computational complexity
In computer science, the computational complexity or simply complexity of an algorithm is the amount of resources required to run it. Particular focus is given to computation time (generally measured by the number of needed elementary operations) ...
of 2
82 and with negligible memory requirements.
At FSE 2007, Joan Daemen and Gilles Van Assche presented a practical attack on the Panama hash function that generates a collision in 2
6 evaluations of the state updating function.
Guido Bertoni,
Joan Daemen, Michaël Peeters, and Gilles Van Assche, at
NIST
The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sci ...
's 2006 Second Cryptographic Hash Workshop, unveiled a Panama variant called
RadioGatún. The hash function workings of RadioGatún does not have the known weaknesses that Panama's hash function has. In turn, RadioGatún inspired the new cryptographic standard
SHA-3.
See also
*
Hash function security summary
References
External links
John Savard's page on Panama
{{Cryptography navbox , hash , stream
Stream ciphers
Broken hash functions
Extendable-output functions