In PKI, which element establishes trust between parties?

In PKI, which element establishes trust between parties?

• A. Routers
• B. Certificates
• C. VLAN IDs
• D. ACLs

Answer: (B)

In PKI, establishing trust between parties comes from digital certificates issued by a trusted authority. A certificate binds a public key to an identity and is signed by a Certificate Authority. When you trust the CA (already stored as a trusted root in your system), you automatically trust any certificate it issues, creating a chain of trust. The certificate itself contains the identity, the public key, the issuer, a validity period, and the issuer’s digital signature. Verifying the certificate involves using the CA’s public key to confirm the signature, ensuring the public key really belongs to the stated identity and is still valid. This mechanism lets parties authenticate each other and establish encrypted communication, such as TLS. The other options don’t establish PKI trust: routers are devices, VLAN IDs are network segmentation labels, and ACLs control traffic permissions.

In PKI, establishing trust between parties comes from digital certificates issued by a trusted authority. A certificate binds a public key to an identity and is signed by a Certificate Authority. When you trust the CA (already stored as a trusted root in your system), you automatically trust any certificate it issues, creating a chain of trust. The certificate itself contains the identity, the public key, the issuer, a validity period, and the issuer’s digital signature. Verifying the certificate involves using the CA’s public key to confirm the signature, ensuring the public key really belongs to the stated identity and is still valid. This mechanism lets parties authenticate each other and establish encrypted communication, such as TLS. The other options don’t establish PKI trust: routers are devices, VLAN IDs are network segmentation labels, and ACLs control traffic permissions.