The Scream cipher is a wordbased stream cipher developed by Shai Halevi, Don Coppersmith and Charanjit Jutla from IBM. The operation of A5/1, a LFSRbased stream cipher used to encrypt mobile phone conversations. ...
Don Coppersmith is a cryptographer and mathematician who was involved in the design of the Data Encryption Standard block cipher at IBM. He has also worked on algorithms for computing discrete logarithms, the cryptanalysis of RSA, methods for rapid matrix multiplication and IBMs MARS cipher, In 1972, Coppersmith obtained...
International Business Machines Corporation (IBM, or colloquially, Big Blue) NYSE: IBM (incorporated June 15, 1911, in operation since 1888) is headquartered in Armonk, NY, USA. The company manufactures and sells computer hardware, software, infrastructure services and consulting services. ...
The cipher is designed as a software efficient stream cipher. The authors describe the goal of the cipher to be a more secure version of the SEAL cipher. SEAL (SoftwareOptimized Encryption Algorithm) is a very fast stream cipher optimised for machines with a 32bit word size and plenty of RAM. The first version was published by Phil Rogaway and Don Coppersmith in 1994. ...
The general design of Scream is close to the design of SEAL with block cipherlike round functions. There are two versions of Scream. One of them, ScreamF, reuses the Sboxes from the Advanced Encryption Standard (AES) block cipher, while the other, Scream, internally generates new, keydependent Sboxes as part of the initialization phase. The round function is also based on the AESround function, but is narrower, 64 bits instead of 128 bits. Encryption Decryption In cryptography, a block cipher is a symmetric key cipher which operates on fixedlength groups of bits, termed blocks, with an unvarying transformation. ...
In cryptography, a substitution box (or Sbox) is a basic component of symmetric key algorithms. ...
General Designer(s) Vincent Rijmen and Joan Daemen First published 1998 Derived from Square (cipher) Cipher(s) based on this design Crypton (cypher), Anubis (cipher), GRAND CRU Algorithm detail Block size(s) 128 bits note Key size(s) 128, 192 or 256 bits note Structure Substitutionpermutation network Number of...
The cipher uses a 128bit key^{[citation needed]} and a full 128bit nonce, down to about 5 cycles/Byte on modern, RISClike processors. Reduced Instruction Set Computer (RISC), is a microprocessor CPU design philosophy that favors a smaller and simpler set of instructions that all take about the same amount of time to execute. ...
The cipher was presented at the Fast Software Encryption (FSE) conference in 2002.
References
 Scream: a softwareefficient stream cipher (pdf)
