=head1 NOTES
Single-key DES is insecure due to its short key size. ECB mode is
-not suitable for most applications; see L<DES_modes(7)|DES_modes(7)>.
+not suitable for most applications; see L<des_modes(7)|des_modes(7)>.
The L<evp(3)|evp(3)> library provides higher-level encryption functions.