SNOW
Encyclopedia
SNOW 1.0, SNOW 2.0, and SNOW 3G are word-based synchronous stream ciphers developed by Thomas Johansson and Patrik Ekdahl at Lund University
.
project. The cipher has no known intellectual property or other restrictions. The cipher works on 32-bit words and supports both 128- and 256-bit keys. The cipher consists of a combination of a LFSR and a Finite State Machine
(FSM) where the LFSR also feeds the next state function of the FSM. The cipher has a short initialization phase and very good performance on both 32-bit processors and in hardware.
During the evaluation, weaknesses were discovered and as a result, SNOW was not included in the NESSIE suite of algorithms. The authors have developed a new version, version 2.0 of the cipher, that solves the weaknesses and improves the performance.
During ETSI SAGE evaluation, the design was further modified to increase its resistance against algebraic attacks with the result named SNOW 3G.
project as a reference cipher for the performance evaluation.
SNOW 2.0 is one out of two stream ciphers chosen for ISO/IEC
standard IS 18033-4 (the other one is MUGI
).
SNOW 3G is chosen as the stream cipher for the 3GPP
encryption algorithms UEA2 and UIA2.
Lund University
Lund University , located in the city of Lund in the province of Scania, Sweden, is one of northern Europe's most prestigious universities and one of Scandinavia's largest institutions for education and research, frequently ranked among the world's top 100 universities...
.
History
SNOW 1.0, originally simply SNOW, was submitted to the NESSIENESSIE
NESSIE was a European research project funded from 2000–2003 to identify secure cryptographic primitives. The project was comparable to the NIST AES process and the Japanese Government-sponsored CRYPTREC project, but with notable differences from both...
project. The cipher has no known intellectual property or other restrictions. The cipher works on 32-bit words and supports both 128- and 256-bit keys. The cipher consists of a combination of a LFSR and a Finite State Machine
Finite state machine
A finite-state machine or finite-state automaton , or simply a state machine, is a mathematical model used to design computer programs and digital logic circuits. It is conceived as an abstract machine that can be in one of a finite number of states...
(FSM) where the LFSR also feeds the next state function of the FSM. The cipher has a short initialization phase and very good performance on both 32-bit processors and in hardware.
During the evaluation, weaknesses were discovered and as a result, SNOW was not included in the NESSIE suite of algorithms. The authors have developed a new version, version 2.0 of the cipher, that solves the weaknesses and improves the performance.
During ETSI SAGE evaluation, the design was further modified to increase its resistance against algebraic attacks with the result named SNOW 3G.
Use
SNOW has been used in the ESTREAMESTREAM
eSTREAM is a project to "identify new stream ciphers suitable for widespread adoption", organised by the EU ECRYPT network. It was set up as a result of the failure of all six stream ciphers submitted to the NESSIE project. The call for primitives was first issued in November 2004. The project was...
project as a reference cipher for the performance evaluation.
SNOW 2.0 is one out of two stream ciphers chosen for ISO/IEC
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
standard IS 18033-4 (the other one is MUGI
MUGI
In cryptography, MUGI is a pseudorandom number generator designed for use as a stream cipher. It has been recommended for Japanese government use by the CRYPTREC project.MUGI takes a 128-bit secret key and a 128-bit initial vector...
).
SNOW 3G is chosen as the stream cipher for the 3GPP
3GPP
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
encryption algorithms UEA2 and UIA2.