VFP provides two ways to secure identity attributes between an instance of OpenSSO Enterprise and an application:
Symmetric involves the use of a shared secret key known only to the participants in the communication. The key is agreed upon beforehand and will be used to encrypt and decrypt the message.
Asymmetric uses two separate keys for encryption and the corresponding decryption - one public and one private. The information is encrypted with a public key known to all and decrypted, by the recipient only, using a private key to which no one else has access. This process is known as a public key infrastructure. On the identity provider side, the public key must be added to the OpenSSO Enterprise keystore. The private key must be stored in a protected keystore (such as a Hardware Security Module) for access by the identity provider application. On the service provider side, the private key must be added to the OpenSSO Enterprise keystore, and the public key stored in a keystore, local to the service provider application.
Both mechanisms result in an encrypted string (referred to as a cryptostring) generated for the asserted attributes. The symmetric cryptostring is a SHA-1 hash of the attributes. The asymmetric cryptostring is a digital signature of the attributes.
As each pairing of application to OpenSSO Enterprise instance is independent, different applications involved can use different security methods.