This package encrypts your text using Hill Cipher Technique. Hill ciphers are an application of linear algebra to cryptology (the science of making and breaking codes and ciphers).

Let the order of the encryption key be N (as it is a square matrix). Your text is divided into batches of length N and converted to numerical vectors by a simple mapping starting with A=0 and so on.

The key is then multiplied with the newly created batch vector to obtain the encoded vector. After each multiplication modular 36 calculations are performed on the vectors so as to bring the numbers between 0 and 36 and then mapped with their corresponding alphanumerics.

While decrypting, the decrypting key is found which is the inverse of the encrypting key modular 36. The same process is repeated for decrypting to get the original message back.

from pycipher import HillCipher
obj = HillCipher("beaf")
print(hc.encrypt("Love Python"))
print(hc.decrypt("PITTOO"))

https://apprendre-en-ligne.net/crypto/hill/Hillciph.pdf