Two processing elements in a single platform may communicate securely to allow the platform to take advantage of the certain cryptographic functionality in one processing element. A first processing element, such as a bridge, may use its cryptographic functionality to request a key exchange with a second processing element, such as a graphics engine. Each processing element may include a global key which is common to the two processing elements and a unique key which is unique to each processing element. A key exchange may be established during the boot process the first time the system boots and, failing any hardware change, the same key may be used throughout the lifetime of the two processing elements. Once a secure channel is set up, any application wishing to authenticate a processing element without public-private cryptographic function may perform the authentication with the other processing element which shares a secure channel with the first processing element.