dm-crypt ========= Device-Mapper's "crypt" target provides transparent encryption of block devices using the kernel crypto API. Parameters: Encryption cipher and an optional IV generation mode. (In format cipher[:keycount]-chainmode-ivopts:ivmode). Examples: des aes-cbc-essiv:sha256 twofish-ecb /proc/crypto contains supported crypto modes Key used for encryption. It is encoded as a hexadecimal number. You can only use key sizes that are valid for the selected cipher. Multi-key compatibility mode. You can define keys and then sectors are encrypted according to their offsets (sector 0 uses key0; sector 1 uses key1 etc.). must be a power of two. The IV offset is a sector count that is added to the sector number before creating the IV. This is the device that is going to be used as backend and contains the encrypted data. You can specify it as a path like /dev/xxx or a device number :. Starting sector within the device where the encrypted data begins. Example scripts =============== LUKS (Linux Unified Key Setup) is now the preferred way to set up disk encryption with dm-crypt using the 'cryptsetup' utility, see http://clemens.endorphin.org/cryptography [[ #!/bin/sh # Create a crypt device using dmsetup dmsetup create crypt1 --table "0 `blockdev --getsize $1` crypt aes-cbc-essiv:sha256 babebabebabebabebabebabebabebabe 0 $1 0" ]] [[ #!/bin/sh # Create a crypt device using cryptsetup and LUKS header with default cipher cryptsetup luksFormat $1 cryptsetup luksOpen $1 crypt1 ]]