I am using the d3des package. So far I have been using the normal DES routines. I have recently decided to use the tripple-DES routines but the documentation ( == *.c and *.h ) didnt seem too clear on the point. From what I understand so far it seems that Ddes() is used for both double and triple encryption (???) for 64bits in 64bits out. this is the test code I did, it works, I'd just like to know for sure if it is using triple des (3*56 bit keys). thanx. #include "d3des.h" unsigned long enkey[96],dekey[96]; main() { char *a,b[100],*k; strcpy(b,"this is a test"); k="testing123423456789212345678"; des3key(k,0); cp3key(enkey); /* set up long keys , encrypt */ des3key(k,1); cp3key(dekey); /* decrypt */ use3key(enkey); Ddes(b,b); /* encrypt b */ write(1,b,8); use3key(dekey); Ddes(b,b); /* decrypt b */ write(1,b,8); }