Getting 88bytes cipher output from 48bytes input in AES
I don't think it's useful spending time on trying to understand that paper, but if you look at the screenshots and compare to their "character counts", you see that they are counting base64 characters and including the padding characters in the count.

That means "88 characters" could be one IV + three blocks of AES output (512 bits in base 64 = 85.33 + 2.67 padding).