Abstract: Various embodiments herein describe methods for enhancing the Hill cipher by inserting a small amount of noise into the ciphertext. Encryption and decryption using this enhanced Hill cipher can be performed quickly. In particular, a pair of a public key matrix and a private key matrix can be derived from any text including, for example, user-specified text or codes, e.g., a user password. Keys can be generated quickly on-the-fly and therefore do not need to be stored on storage devices, e.g., hard drives. Communication between two computing devices can be secured by encrypting messages using the public key matrix and sending the encrypted data from a first computing device to a second computing device. The second computing device is able to decrypt the messages using at least the corresponding private key matrix.