I want to encrypt a file using AES-256. How can I do that quickly and easily, and how can I - or someone else -decrypt it again?
If you want the encryption to be platform independent, you can use openssl:
You can get openssl to
Note that you have a choice of ciphers and modes of operation. For normal use, I recommend aes 256 in CBC mode. These are the ciphers modes you have available (only counting AES):
OpenSSL will ask you for a password. This is not an encryption key, it is not limited to 32 bytes! If you're going to transfer files with someone else, your shared secret should be very strong. You can use this site to get a sense of how good your password is:
7z (when the password option is used) uses a 256bit AES encryption (with SHA256 key stretching).
Install it (
For decryption, right click on the .7z file and choose Extract here.
The linked website contains an open-source 256-bit aes encrypt/decrypt tool and is multiplatform - MacOs, Windows, Linux and others through Java.
You could backup and encrypt your home folder using the syntax:
Download the binaries or source-code from the website.
download Truecrypt, make your own container or encrypt your files. works fine in windows and linux.