Each set of eight rounds is termed an octet ; a different S-box is used in each octet.

The Rijndael S-box is a matrix ( square array of numbers ) used in the Rijndael cypher, also known as the Advanced Encryption Standard ( AES ) cryptographic algorithm.

In the < tt > SubBytes </ tt > step, each byte in the state matrix is replaced with a < tt > SubByte </ tt > using an 8-bit substitution box, the Rijndael S-box.

To avoid attacks based on simple algebraic properties, the S-box is constructed by combining the inverse function with an invertible affine transformation.

The S-box is also chosen to avoid any fixed points ( and so is a derangement ), and also any opposite fixed points.

In the most basic type of block cipher, a substitution-permutation network, analysis is concentrated primarily on the S-boxes, the only nonlinear part of the cipher ( i. e. the operation of an S-box cannot be encoded in a linear equation ).

An S-box is usually not simply a permutation of the bits.

* The reason for diffusion is the following: If one changes one bit of the plaintext, then it is fed into an S-box, whose output will change at several bits, then all these changes are distributed by the P-box among several S-boxes, hence the outputs of all of these S-boxes are again changed at several bits, and so on.

Bits in the left half are first shuffled by 9-bit substitution box ( S-box ) S9 and the result is XOR ' ed with

Bits of the right half are shuffled by 7-bit S-box S7 and the result is XOR ' ed with

Bits in the right half are then shuffled by 9-bit S-box S9 and the result is XOR ' ed with

Finally the bits of the left half are shuffled by 7-bit S-box S7 and the result is XOR ' ed with

In a round, the least significant byte of half of the block is passed into the 8 × 32-bit S-box.

The S-box output is then combined ( using XOR ) with the other 32-bit half.

The S-box of AES appears to be especially vulnerable to this type of analysis, as it is based on the algebraically simple inverse function.

In each round, subkey material is XORed with the 1-byte sub-blocks of data, then fed through an S-box, the output of which is then XORed with another sub-block of data.

The S-box is derived from the United States Declaration of Independence ( to show that Scott had nothing up his sleeve ).

The S-box is generated by determining the multiplicative inverse for a given number in GF ( 2 < sup > 8 </ sup >) = GF ( 2 )/( x < sup > 8 </ sup > + x < sup > 4 </ sup > + x < sup > 3 </ sup > + x + 1 ), Rijndael's finite field ( zero,

This will generate the following S-box, which is represented here with hexadecimal notation:

For example, the value < tt > 0x9a </ tt > is converted in to < tt > 0xb8 </ tt > by Rijndael's S-box.

Fifth, the S-box output bits are permuted so that each S-box's outputs are routed to each 4-bit field of 32-bit word, including 2 of the 8 " overlap " bits duplicated during the next round's expansion.

For example, comparative analysis of upstream regions of several genes expected to be co-regulated led to the description of the S-box ( now the SAM-I riboswitch ), the THI-box ( a region within the TPP riboswitch ), the RFN element ( now the FMN riboswitch ) and the B < sub > 12 </ sub >- box ( a part of the cobalamin riboswitch ), and in some cases experimental demonstrations that they were involved in gene regulation via an unknown mechanism.

Three distinct SAM riboswitches are known: SAM-I ( originally called S-box ), SAM-II and the S < sub > MK </ sub > box riboswitch.

The nonlinear layer in Rijndael uses an 8 × 8 S-box whereas Serpent uses eight different 4 × 4 S-boxes.

Rather, a good S-box will have the property that changing one input bit will change about half of the output bits ( or an avalanche effect ).

A single typical S-box or a single P-box alone does not have much cryptographic strength: an S-box could be thought of as a substitution cipher, while a P-box could be thought of as a transposition cipher.

A good P-box has the property that the output bits of any S-box are distributed to as many S-box inputs as possible.

This continues, replacing the entire P-array and all the S-box entries.

Another variant, described in ( US Patent 3, 796, 830 ; Nov 1971 ), uses a 64-bit key operating on a 32-bit block, using one addition mod 4 and a singular 4-bit S-box.

The round function in Serpent consists of key-mixing XOR, thirty-two parallel applications of the same 4 × 4 S-box, and a linear transformation, except in the last round, wherein another key-mixing XOR replaces the linear transformation.

The S-box substitution in the round function consists of eight 4 × 4 S-boxes.

For transformation involving reasonable number of n message symbols, both of the foregoing cipher systems ( the S-box and P-box ) are by themselves wanting.

Shannon suggested using a combination of S-box and P-box transformation — a product cipher.

WAKE uses an S-box with 256 entries of 32-bit words.

diffuse the S-box outputs as quickly as possible.

In the first instance, `` mimesis '' is here used to mean the recalling of experience in terms of vivid images rather than in terms of abstract ideas or conventional designations.

A dominant motive is the poet's longing for his homeland and its boyhood associations: `` Not men-folk, but the fields where I would stray, The stones where as a child I used to play ''.

So in these pages the term `` technology '' is used to include any and all means which could amplify, project, or augment man's control over himself and over other men.

But what a super-Herculean task it is to winnow anything of value from the mud-beplastered arguments used so freely, particularly since such common use is made of cliches and stereotypes, in themselves declarations of intellectual bankruptcy.

This text from Dr. Huxley is sometimes used by enthusiasts to indicate that they have the permission of the scientists to press the case for a wonderful unfoldment of psychic powers in human beings.

The men who speculate on these institutions have, for the most part, come to at least one common conclusion: that many of the great enterprises and associations around which our democracy is formed are in themselves autocratic in nature, and possessed of power which can be used to frustrate the citizen who is trying to assert his individuality in the modern world ''.

Properly used, the present book is an excellent instrument of enlightenment.

This prospect did not please Mrs. King any more than did the possibility that her daughter might marry a Bohemian, but she used it to suggest to Thompson that, `` It is not in her nature to love you ''.

On the other hand, the consensus of opinion is that, used with caution and in conjunction with other types of evidence, the native sources still provide a valid rough outline for the English settlement of southern Britain.

The trouble with this machinery is that it is not used and the reason that it is not used is the absence of a conscious sense of community among the free nations.

In addition to his experiments in reading poetry to jazz, Patchen is beginning to use the figure of the modern jazz musician as a myth hero in the same way he used the figure of the private detective a decade ago.

When different colors are used, she is just as likely to color trees purple, hair green, etc..

Berlin is merely being used by Moscow as a stalking horse.

The collection of information is meaningless unless it is understood and used for a definite purpose.

This is used as a reference for comparing the ohmic heating and the electrical energy obtained from the measured current through the element and the measured voltage across the element.