Which of the following is a characteristic of Public Key Infrastructure (PKI)?

Public-key cryptosystems are actually significantly slower than symmetric-key cryptosystems due to the mathematical complexity of asymmetric operations like RSA.

In PKI, a Certificate Authority (CA) issues digital certificates that bind a public key to an identity and signs those certificates digitally. When a digital signature is verified, the public key embedded in the signed certificate is used, effectively distributing public keys within the signed certificate/signature infrastructure. This binding through CA-signed certificates is the foundational mechanism that enables trusted public key distribution in PKI.

PKI exists precisely because public key distribution still requires authenticated infrastructure - Certificate Authorities provide the trusted chain needed to verify that a public key genuinely belongs to the claimed owner.

Technical non-repudiation via digital signatures is one of the primary capabilities that PKI and asymmetric cryptography provide, not a feature they lack.