UPSC Prelims 2020 question on Public Key Infrastructure

Public Key Infrastructure (PKI) is a technology for authenticating users and devices in the digital world. The basic idea is to have one or more trusted parties digitally sign documents certifying that a particular cryptographic key belongs to a particular user or device.

PKI is used in the context of digital security infrastructure — it provides secure communications, digital signatures, and authentication in the digital environment.

Hence option (a) — Digital security infrastructure — is the correct answer.