For normal use, I recommend aes 256 in CBC mode. Note that you have a choice of ciphers and modes of operation.

U2FsdGVkX192dXI7yHGs/4Ed+圎C3ejXFINKO6Hufnc= Verifying - enter aes-256-cbc encryption password: It'll look like this: stefano:~$ openssl aes-256-cbc -in attack-plan.txt -a This way, you can paste the ciphertext in an email message, for example. You can get openssl to base64-encode the message by using the -a switch on both encryption and decryption. Openssl aes-256-cbc -d -in message.enc -out plain-text.txt

Openssl aes-256-cbc -in attack-plan.txt -out message.enc

you can't just use encryption to communicate securely)

For many types of security, encryption is simply not enough (e.g.

Additionally, this method doesn't authenticate the ciphertext, which means an attacker can modify or corrupt the contents without you noticing.

As was pointed out in the comments, this method uses a naive key derivation function, so your password needs to be superlatively good in order for you to have a chance of being secure.

Please note: You can use this to hide birthday-gift-ideas.txt from your roommate, but don't expect it to be secure against a determined attacker! If you want very simple platform independent encryption, you can use openssl.

OTR with Pidgin if you want secure instant messaging.

Use GPG if you want to communicate securely via email.

Encrypt your home directory (very easy to do with the Ubuntu installer).

Use a password manager like Keyring for passwords.

Think about your use-case, maybe something other than plain AES is better suited. Unfortunately, there is no easy solution to securing your stuff.

Zip encrypt file