I hope this ius the right place to post problems to the mailgroup linux-crypto, if not, please excuse my ignorance. I think I have followed the instructions in your HOWTO to patch my linux 2.2.18 system and utils for crpto, but I get the following error when using losetup with any of the new ciphers. [root@xxxxxxxxx dlambert]# losetup -e twofish /dev/loop0 /tmp/.crypto Password : ioctl: LOOP_SET_STATUS: Invalid argument This does not occur if I use XOR or NONE I do seem to be getting the crypto modules installed in the kernel as witnessed by the following extract from my dmesg log. MD5 Message Digest Algorithm (c) RSA Systems, Inc cryptoapi: Registered md5 (5) cryptoapi: Registered twofish (9) cryptoapi: Registered twofish-cbc (65545) cryptoapi: Registered serpent (7) cryptoapi: Registered serpent-cbc (65543) cryptoapi: Registered blowfish (4) cryptoapi: Registered blowfish-cbc (65540) cryptoapi: Registered des_ede3 (12) cryptoapi: Registered des_ede3-cbc (65548) Any suggestions as to where to look next would be greatly appreciated. Best regards, David Lambert Linux-crypto: cryptography in and on the Linux system Archive: http://mail.nl.linux.org/linux-crypto/