elpa-ps-ccrypt provides low-level support for reading, writing, and
 loading files encrypted with ccrypt. It hooks into the low-level file I/O
 functions (including write-region and insert-file-contents) so that they
 automatically encrypt or decrypt a file if the file appears to need it
 (based on the extension of the file name). Packages like Rmail, VM, GNUS,
 and Info should be able to work with encrypted files without modification.