man amcrypt-ossl (8): crypt program for Amanda symmetric data encryption using OpenSSL

SYNOPSIS

amcrypt-ossl [-d]

DESCRIPTION

amcrypt-ossl

uses OpenSSL to encrypt and decrypt data. OpenSSL is available from www.openssl.org. OpenSSL offers a wide variety of cipher choices ( amcrypt-ossl defaults to 256-bit AES) and can use hardware cryptographic accelerators on several platforms.

amcrypt-ossl will search for the OpenSSL program in the following directories: /bin:/usr/bin:/usr/local/bin:/usr/ssl/bin:/usr/local/ssl/bin.

PASSPHRASE MANAGEMENT

amcrypt-ossl uses the same pass phrase to encrypt and decrypt data. It is very important to store and protect the pass phrase properly. Encrypted backup data can only be recovered with the correct passphrase.

OpenSSL's key derivation routines use a salt to guard against dictionary attacks on the pass phrase; still it is important to pick a pass phrase that is hard to guess. The Diceware method (see www.diceware.com) can be used to create passphrases that are difficult to guess and easy to remember.