Question

In the SubBytes step, each byte in the matrix is substituted for another byte using an 8-bit substitution box, called the _____________.

Answer 1

In the Sub Bytes step, each byte in the matrix is substituted for another byte using an 8-bit substitution box called the S-Box. The S-Box is a lookup table that provides a non-linear substitution of each byte.

Step-by-step explanation:

In the Sub Bytes step of the AES (Advanced Encryption Standard) algorithm, each byte in the matrix is substituted for another byte using an 8-bit substitution box, called the S-Box.

The S-Box is a lookup table that provides a non-linear substitution of each byte. It takes in a 8-bit input and outputs an 8-bit value, replacing each byte of the matrix with a different byte based on a mathematical formula.

For example, if the input byte is 0x53, the S-Box would substitute it with the output byte 0xED. This step improves resistance to cryptographic attacks and enhances the security of the AES algorithm.