In cryptography, the socalled product ciphers are a certain kind of ciphers, where the (de)ciphering of data is done in "rounds". The general setup of each round is the same, except for some hardcoded parameters and a part of the cipher key, called a subkey. A key schedule is an algorithm that, given the key, calculates the subkeys for these rounds.
Knudsen and Mathiassen (2004) give some experimental evidence that indicate that the key schedule plays a part in providing strength against linear and differential cryptanalysis. For toy Feistel ciphers, it was observed that those with complex and welldesigned key schedules can reach a uniform distribution for the probabilities of differentials and linear hulls faster than those with poorlydesigned key schedules.
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In cryptography, the socalled product ciphers are a certain kind of ciphers, where the decryption of data is done in "rounds". The general setup of each round is the same, except for some hardcoded parameters and a part of the cipher key, called a subkey. A key schedule is an algorithm that, given the key, calculates the subkeys for these rounds.
Knudsen and Mathiassen (2004) give some experimental evidence that indicate that the key schedule plays a part in providing strength against linear and differential cryptanalysis. For toy Feistel ciphers, it was observed that those with complex and welldesigned key schedules can reach a uniform distribution for the probabilities of differentials and linear hulls faster than those with poorlydesigned key schedules.
