Refer to the exhibit: BGPsec is implemented on R1.

 BGPsec enhances BGP by adding a layer of security for the AS path attribute. When BGPsec is implemented, updates from eBGP peers include a BGPsec attribute sequence with a public key hash and digital signature. This ensures the authenticity and integrity of the AS path, preventing unauthorized AS numbers from being inserted. References: = Implementing and Operating Cisco Service Provider Network Core Technologies course materials.