MMB (cipher)

{{Short description|Block cipher}}

{{Infobox block cipher

| name = MMB

| designers = Joan Daemen

| publish date = 1993

| derived from = IDEA

| derived to = ABC

| related to =

| key size = 128 bits

| block size = 128 bits

| structure = Substitution–permutation network[http://sac.ucalgary.ca/sites/sac.math.ucalgary.ca/files/u5/16_MMB_block.pdf Slide 4] {{Dead link|date=February 2016}}

| rounds = 6

| cryptanalysis = Key recovery using 2⁶⁷ chosen plaintexts{{citation

| author = K. Jia and J. Chen and M. Wang and X. Wang

| title = Practical-time Attack on the Full MMB Block Cipher

| year = 2010

| url = https://eprint.iacr.org/2010/211/

| format = PDF

| access-date = 2010-04-24 }}

}}

In cryptography, MMB (Modular Multiplication-based Block cipher) is a block cipher designed by Joan Daemen as an improved replacement for the IDEA cipher.{{cite conference

|author=Joan Daemen |author2=René Govaerts |author3=Joos Vandewalle

| title = Block Ciphers Based on Modular Arithmetic

| book-title = Proceedings of the 3rd Symposium on: State and Progress of Research in Cryptography

| pages = 80–89

| publisher = Fondazione Ugo Bordoni

| date = 1993

| citeseerx = 10.1.1.52.2614

}} Modular multiplication is the central element in the design. Weaknesses in the key schedule were identified by Eli Biham, and this, together with the cipher's not having been designed to resist linear cryptanalysis, meant that other designs were pursued instead, such as 3-Way.

MMB has a key size and block size of 128 bits.