How is an AES S-Box cyclically shifted to the left? I'm trying to an implement an enhanced version of AES which was proposed recently. The link to the paper is here: http://sdiwc.net/digital-library/enhancing-aes-using-novel-block-key-generation-algorithm-and-key-dependent-sboxes

In their proposed algorithm, a unique S-box is created for each round by XOR'ing all 16 bytes of the round key, and cyclically shifting the original static S-Box to the left by that value. I'm new to cryptography in general, and I understand the original AES algorithm well, but I don't understand what the authors mean by cyclically shifting the S-Box. Obviously, each individual byte can't be shifted, since the shift values produced are as high as 127. Is it each row of the S-Box that has to be shifted, or are all 256 bytes lined up somehow and shifted?
Yes they are talking about shifting each individual byte.

In the example in the paper, s-box input 00 becomes input A4 (output 63), 01 becomes A5 (7C), and so on. This is a 92 byte left rotation of the s-box elements, which is equivalent to a 164 byte right rotation, all done mod 256.

Without going into extreme detail, I would strongly recommend against using this... ever, it is not a good idea, and actually makes the cipher weaker. There are only 255 new s-boxes generated using this method, and they are all weaker than the original.

The example s-box given shows the following properties:

Differential Uniformity: 8 (lower is better)
Non-linearity: 94 (higher is better)
AutoCorrelation: 88 (lower is better)
SSI: 260608 (lower is better)


The AES standard s-box has these values for the same properties:

Differential Uniformity: 4 (lower is better)
Non-linearity: 112 (higher is better)
AutoCorrelation: 32 (lower is better)
SSI: 133120 (lower is better)


The new s-box also inherits the undesirable properties of the original, such as simple algebraic representation and CCZ equivalence.