DataCrypt is a fast, simple, and free data encryption & decryption app that can encrypt & decrypt data & strings securely, using AES-128/256.

DataCrypt is an impressively small 60Kb, is fast and has a very easy to use interface. You can open a file using the File menu and click on decrypt. When you set your password, pressing F1 shows the password. Drag and drop isn't supported, but that's not a big deal.

You might want to take a peek at settings where you can change the encryption algorithm, cipher mode, padding mode, size, and PBKDF key iterations. Status is shown at the bottom of the app with your current settings. You can also copy anything to the clipboard as needed.

DataCrypt Features:

Secure data encryption with AES-128/256 (password-based encryption, pure random IV & salt)

Changeable encryption settings (cipher mode, padding mode, salt size, and PBKDF key iterations)

Easy to use, simple and very fast

Lightweight and portable

DataCrypt when last updated was considered a beta, but you won't know that. It's well laid out, fast, easy to use and well thought out in its presentation and usage. DataCrypt is an example of simplicity and ease of use that other software developers could learn from.