MESH (cipher)

This article is about the block cipher. For other uses, see Mesh (disambiguation).

In cryptography, MESH is a block cipher designed in 2002 by Jorge Nakahara, Jr., Vincent Rijmen, Bart Preneel, and Joos Vandewalle. MESH is based directly on IDEA and uses the same basic operations.

MESH

General
Designers	Nakahara, Rijmen, Preneel, Vandewalle
First published	2002
Derived from	IDEA
Cipher detail
Key sizes	128, 192, or 256 bits
Block sizes	64, 96, or 128 bits
Structure	Lai–Massey scheme
Rounds	8.5, 10.5, or 12.5
Best public cryptanalysis
2 rounds can be broken using 128, 161, or 225 known plaintexts

MESH is actually a family of 3 variant ciphers with block sizes of 64, 96, and 128 bits.^[1] The key size is twice the block size. The number of rounds is 8.5, 10.5, or 12.5, depending on the block size. The algorithm uses a Lai–Massey scheme based on IDEA's, but with a larger round structure, or "MA-box". MESH also has a more complex key schedule than IDEA, intended to prevent weak keys and other insecure patterns in subkeys.