| Horde_Crypt | Provides an API for various cryptographic systems used by Horde applications. |
| Horde_Crypt_Exception | Exception handler for the horde/Crypt package. |
| Horde_Crypt_Pgp | A framework for Horde applications to interact with the GNU Privacy Guard program ("GnuPG"). GnuPG implements the OpenPGP standard (RFC 4880). |
| Horde_Crypt_Pgp_Backend | Abstract backend class to implement PGP functionality. |
| Horde_Crypt_Pgp_Backend_Binary | PGP backend that uses the gnupg binary. |
| Horde_Crypt_Pgp_Keyserver | Provides methods to connect to a PGP keyserver. |
| Horde_Crypt_Pgp_Parse | Provides methods to parse PGP armored text data. |
| Horde_Crypt_Smime | Library to interact with the OpenSSL library and implement S/MIME. |
| Horde_Crypt_Translation | Horde_Crypt_Translation is the translation wrapper class for Horde_Crypt. |