Public/private key based encryption is very popular because of the strength it sets in encryption, specially above 1024 bits. Now there are external library to encrypt data using RSA encryption like RSA in phpclasses.org - the fun is we were also using this library in one of our ZF based project. But last week I've found that there is a hidden gem in the Library/Zend/Crypt folder (Zend_Crypt_Rsa) which can do the same thing using openssl library.

He couldn't find much in the way of documentation for the component, so he wrote up how to use it in three easy steps:

• Create your RSA public/private key using ssh-keygen
• Encrypt data using your public key
• Decrypt the cipher

The Zend_Crypt_Rsa makes it simple to encrypt/decrypt the data, just taking in a passphrase, a path to the RSA key file and the message contents.