Is there any security risk in encrypting parts of blocks twice? I'd like to get around block sizes and make encrypted messages just as long as the unencrypted ones:
Block 1: Byte 0 - 7
Block 2: Byte 8 - 15
Block 3: Byte 16 - 23
Block 4: Byte 21 - 29
In this example blocks 3 and 4 overlap by 2 bytes. I plan on using CAST-128.
Thank you very much for helping!
Florian