Mir-1
{{Short description|Stream cipher}}
{{About|cryptology|other uses|Mir 1 (disambiguation){{!}}Mir 1}}
In cryptography, Mir-1 is a software-oriented stream cipher algorithm developed by Alexander Maximov. The algorithm was submitted to the eSTREAM project of the eCRYPT network in 2005. Mir-1 is named after the Russian space station Mir.{{cite web |last1=Maximov |first1=Alexander |title=A New Stream Cipher 'Mir-1' |url=https://www.ecrypt.eu.org/stream/ciphers/mir1/mir1.ps |access-date=14 February 2023}}
Mir-1 uses a multiword T-function with four 64-bit words. The data in each word is processed, generating a keystream.{{cite journal |last1=Tsunoo |first1=Yukiyasu |last2=Saito |first2=Teruo |last3=Kubo |first3=Hiroyasu |last4=Suzaki |first4=Tomoyasu |title=Cryptanalysis of Mir-1: A T-Function-Based Stream Cipher |journal=IEEE Transactions on Information Theory |date=November 2007 |volume=53 |issue=11 |pages=4377–4383 |doi=10.1109/TIT.2007.907340 |s2cid=6501255 |url=https://ieeexplore.ieee.org/document/4373435 |access-date=14 February 2023|url-access=subscription }} Its key size is 128 bits, and its IV is 64 bits.
The designer claimed that Mir-1 had a security level of 2128, i.e., that it could not be "broken" faster than an exhaustive search. At SASC 2006, a successful key-recovery attack on Mir-1 was shown. Maximov did not dispute the attack, and the algorithm was archived after Phase 1 by the eSTREAM committee.{{cite web |last1=Bernstein |first1=Daniel |title=Which eSTREAM ciphers have been broken? |url=https://cr.yp.to/streamciphers/broken-20080330.pdf |access-date=14 February 2023}}