encrypt file.txt to file.enc using 256-bit AES in CBC mode

openssl enc -aes-256-cbc -salt -in file.txt -out file.enc

the same, only the output is base64 encoded for, e.g., e-mail

openssl enc -aes-256-cbc -a -salt -in file.txt -out file.enc

decrypt binary file.enc

openssl enc -d -aes-256-cbc -in file.enc

decrypt base64-encoded version

openssl enc -d -aes-256-cbc -a -in file.enc

thanks Mark, http://bolusmjak.posterous.com/

to begin to properly secure your linux computer with ssh your sshd configuration file should contain the lines below.  These lines prevent root access, force public key authentication (no password to crack) and restrict access to named users only.

PermitRootLogin no

PasswordAuthentication no

RSAAuthentication yes

PubkeyAuthentication yes

AllowUsers babyman evan

touch temp -t 200910011130

touch ntemp -t 200910011630

find / -cnewer temp -and ! -cnewer ntemp

use the following to set the time between when screen saver activates and when a password is required to access the computer, the time is in seconds (10 in this case)

defaults -currentHost write com.apple.screensaver askForPasswordDelay -int 10