From the aescrypt README.html:
This is a program for encrypting/decrypting streams of data using
Rijndael and Cipher Block Feedback mode (CFB-128).
...
5. This program was deliberately kept extremely simple. It is not
intended to be a full encryption solution, it is intended to be
used within scripts as part of a complete solution. Keychain
management, public key signatures, etc. are all expected to be
done external to this program.
Author: Eric Lee Green
WWW: http://aescrypt.sourceforge.net/