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seen Jan 18 at 19:46

Dec
23
awarded  Supporter
Dec
23
accepted Two-dimensional S-Box
Dec
23
comment Two-dimensional S-Box
Thank you. Your explanation of the development of S-Box really helped my understanding of the issue.
Dec
22
awarded  Editor
Dec
22
revised Two-dimensional S-Box
deleted 33 characters in body
Dec
22
comment Two-dimensional S-Box
My cipher is only example. Consider, that I need several different S-boxes. So I need to construct several good S-boxes. My 4-bit S-box with two level of substitution is equivalent to 16-bit S-box with one level of substitution. So if I right, constructing of 4-bit S-box is simpler, than constructing 16-bit S-box. This simplifies the development of encryption algorithm, in that case when it is necessary with several blocks. If I'm wrong, I'll be glad to hear criticism.
Dec
22
comment Two-dimensional S-Box
I use two different symbols because I want represent that this S-boxes change input message by different way. $S'$ change every row of input message (message is 2-dimensional array 4x4). Output of $S'$ is 2-dimensional array 4x4 too. $S''$ substitute every column of output of $S'$.
Dec
22
comment Two-dimensional S-Box
$S'$ and $S''$ is same 4-input-bits S-box. Where $S_1$ and $S_2$ is 16-input-bits S-boxes. $S'$ change plain-text by rows, i.e. convert all rows. $S''$ change only columns of output of $S'$. While $S_1$ change all plain-text and $S_2$ change all 16-bit of output of $S_1$
Dec
22
asked Two-dimensional S-Box
Nov
21
awarded  Student
Nov
21
accepted Applying differential cryptanalysis to ciphers with addition mod $2^{32}$
Nov
21
awarded  Scholar
Nov
21
comment Applying differential cryptanalysis to ciphers with addition mod $2^{32}$
thank you very much for your answer. ((m1 - k1) mod c) - (m2 - k1) mod c) mod c ==> ((m1 mod c) - (k1 mod c) - (m2 mod c) + (k1 mod c)) mod c ==> ((m1 mod c) - (m2 mod c)) mod c. So we get rid of the key.
Nov
21
reviewed Approve suggested edit on Applying differential cryptanalysis to ciphers with addition mod $2^{32}$
Nov
21
comment Applying differential cryptanalysis to ciphers with addition mod $2^{32}$
@user8911, thank you for the fix.
Nov
21
awarded  Custodian
Nov
21
reviewed Approve suggested edit on Applying differential cryptanalysis to ciphers with addition mod $2^{32}$
Nov
21
asked Applying differential cryptanalysis to ciphers with addition mod $2^{32}$