cryptico.js cryptico-min.js documentation Generating an RSA key pair & public key string Sam wants to send Matt an encrypted message. In order to do this, he first needs Matt's public key string. A public key pair can be generated for Matt like this: // The passphrase used to repeatably generate this RSA key. var PassPhrase = "The Moon is a Harsh Mistress."; // The length of the RSA key, in bits.