What is a Certificate Authority?
A Certificate Authority (CA) is the core component of a public key infrastructure (PKI) responsible for establishing a hierarchical chain of trust. CAs issue the digital credentials used to certify the identity of users. CAs underpin the security of a PKI and the services they support, and therefore can be the focus of sophisticated targeted attacks. In order to mitigate the risk of attacks against Certificate Authorities, physical and logical controls as well as hardening mechanisms, such as hardware security modules (HSMs) have become necessary to ensure the integrity of a PKI.