Kryptor is a portable, cross-platform, Open Source tool for file encryption.
Its newer version is a command-line tool designed to make use of modern and secure cryptographic algorithms. We have included the GUI version, available for those that aren't comfortable working from the command-line, but the author indicates this may not be further developed. The GUI version supports drag n' dropping of files into the interface, and you are prompted as you move through the process of encryption. The command-line version is also straightforward, offering the same secure encryption, it aims to be a simple, user-friendly alternative to GPG.
Kryptor permits you to encrypt files with a password, keyfile, or asymmetric keys; you can also create and verify digital signatures. Encrypting files using a recipient's public key allows for authenticated file sharing allowing you to send data securely. It supports an authenticated comment and pre-hashing for large files. You can also utilize asymmetric key pair generation. The private key is encrypted for protection at rest. It sports a UNIX-style password entry and random passphrase generation. Kryptor allows for random keyfile generation so that any file type can also be used as a keyfile. There is also optional obfuscation of output file names when encrypting files/folders, and for added security, there is optional overwriting of input files.