An algorithm is language agnostic. That is to say that any encryption algorithm should operate the same regardless of wheter it was implemented in Perl, C, COBOL, Fortran, Lisp, etc... So, let's say that you choose DES. There's a DES module for Perl, and I'm sure with a bit of searching, you can find a C implementation of it. You can write your respective programs around those two libraries; your Perl program around the Perl module, and the C program around the C library. Easy, peasy, Japanese-y.