A schryption of a text message is based on a schryption key for defining one or more aspects of an encryption and/or a decryption of the text message. For an encryption of the text message, the schryption key is derived from a user key in the form of an encryption key (e.g., a secret key or a public key), and the text message in the form of plaintext is encrypted as defined, at least partially, by the schryption key to thereby yield a ciphertext. For a decryption of the text message, the schryption key is derived from user key in the form of a decryption key (e.g., a secret key or a private key), and the text message in the form of a ciphertext is decrypted as defined, at least partially, by the schryption key to thereby yield a plaintext.