I have to develop a program using a "secret" locally stored encoded program for a school project. For this I have to decipher the code on the fly to use it. The project recommend the use of AES 256 in CBC mode, but for better performance any suggestion is welcome.
So I have two questions:
I made my own implementation of AES (I know it's not recommended but it's mandatory in the project) and I'm looking to compare it to the fastest software implementation, any idea where to find it?
I was looking for faster cipher but more or less "as secure" than AES to suggest and implement. So far I found quite a few: CLEFIA, Threefish, Salsa20 and LWC:PRESENT, LEA, ASCON(AEAD?). I understand that the security on LWC is far less than standard cryptography(even though the difference is not really clear between SC and LWC) but they don't seem to be broken. Should they be used for my purpose? If not any other suggestion?