DEAL

{{Short description|Block cipher}}

{{Other uses|Deal (disambiguation)}}

{{Infobox block cipher

| name = DEAL

| image = Image:Deal-round-function.svg

| caption = Round function of DEAL

| designers = Lars Knudsen

| publish date = 1998

| derived from = DES

| derived to =

| related to = Ladder-DES

| key size = 128, 192 or 256 bits

| block size = 128 bits

| structure = Nested Feistel network

| rounds = 6 (128- and 192-bit key) or 8 (256-bit key)

| cryptanalysis =

}}

In cryptography, DEAL (Data Encryption Algorithm with Larger blocks) is a symmetric block cipher derived from the Data Encryption Standard (DES). Its design was presented by Lars Knudsen at the SAC conference in 1997, and submitted as a proposal to the AES contest in 1998 by Richard Outerbridge.

DEAL is a Feistel network which uses DES as the round function. It has a 128-bit block size and a variable key size of either 128, 192, or 256 bits; with 128-bit and 192-bit keys it applies 6 rounds, or 8 rounds with 256-bit keys. It has performance comparable to Triple DES, and was therefore relatively slow among AES candidates.