http://deepweb4wt3m4dhutpxpe7d7wxdftfdf4hhag4sizgon6th5lcefloid.onion/blog/darknet-news/what-is-aes-encryption
The columns are treated as polynomials over a finite field and multiplied modulo a fixed polynomial, further scrambling the data. This step ensures that the transformation of each column affects the others, enhancing the algorithm's resistance to cryptographic attacks.