Explains how IKEv2 uses RSA digital signatures and PKI to authenticate peer devices during the establishment of security associations.
A certificate-based authentication method is a network security mechanism that
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uses digital certificates issued by a trusted authority to validate the identity of devices,
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relies on public key cryptography, and
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enables secure exchange of cryptographic keys during the establishment of security associations (SAs).
Certification Authority (CA) interoperability allows Cisco NCS 1004 devices to communicate with CAs, enabling the devices to obtain and use digital certificates. A CA manages certificate requests and issues certificates to participating network devices, ensuring each device receives a unique, validated certificate
In public key cryptography, such as the RSA encryption system, each user has a key pair containing both a public and a private key. The keys act as complements, and anything encrypted with one of the keys can be decrypted with the other. In simple terms, a signature is formed when data is encrypted with a user's private key. The receiver verifies the signature by decrypting the message with the sender's public key. The fact that the message could be decrypted using the sender's public key indicates that the holder of the private key, the sender, must have created the message. This process relies on the receiver's having a copy of the sender's public key and knowing with a high degree of certainty that it does belong to the sender and not to someone pretending to be the sender.
With certificate-based authentication, each router authenticates itself to a remote peer by sending its CA-issued digital certificate and performing public key cryptography. A router proves its identity by using an RSA digital signature, which is verified by the remote peer using the public key encapsulated within the certificate. The validation process works because all participating routers trust the CA as a common authenticating authority.