crypt(2m)

NAME

crypt - Encrypted file mode

SYNOPSIS

crypt Mode

Y - mode line letter.

DESCRIPTION

crypt mode enables encrypted files to be loaded and saved for security purposes. The key can be set at any time using the command set-encryption-key(2). Warning, take care if setting this as a global mode, it can have side-effects.

The encryption algorithm uses AES in a chained block form and 256 bit key, at time of writing this should be considered as secure as the password used. When you write out text, if crypt mode is active and there is no encryption key, MicroEmacs will ask:

<file-name> password:

Type in a word or phrase of at least five and up to 128 characters for the encryption to use. If you look at the file which is then written out, it should be indistinguishable to random data, also if you save the file again, without any changes to the unencrypted data, the content be completely different. To read such a file later, use find-cfile(3) to load ciphertext files, you will be asked for the password before the file is read.

SEE ALSO

Operating Modes, buffer-mode(2), find-cfile(3), global-mode(2), set-encryption-key(2), AES(2).

(c) Copyright JASSPA 2025
Last Modified: 2023/02/21
Generated On: 2025/09/29