thanks for your answer, now,would you please tell me how PAM calls crypt() and which pam library *.so ? Also is it a good idea to implement AES instead of crypt() ? I have enough C knowledge and a C compiler :) but not familiar with linux kernel. I have searched many sites and found some patches which adds AES support to linux kernel but my goal is using AES as default, in REDHAT 8.2 there are some DOCS about PAM and PAM editing but it is not enough for me. Would you please suggest me some docs,sites or books related to this subject? have a nice day loves from Turkey -- _______________________________________________ Tum spor urunlerini www.sporx.com 'da bulabilirsiniz Powered by Outblaze _______________________________________________ Pam-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/pam-list