What is PKI? Why is it so important in information security?

PKI stands for Public Key Infrastructure. It is a framework of policies, procedures, software, hardware, and people required to manage digital certificates and public-key encryption. PKI creates and manages digital certificates which bind public keys with the identities of their owners.

PKI is important in information security because it enables secure communication and transactions over insecure networks like the internet. It provides services such as:

• Authentication: Verifies the identity of users, devices, or applications. For example, a web browser uses PKI to verify the identity of a website through its SSL/TLS certificate.
• Confidentiality: Protects sensitive data from unauthorized access using encryption. Data encrypted with a recipient's public key can only be decrypted with their corresponding private key.
• Integrity: Ensures that data has not been altered during transmission. Digital signatures, which are a component of PKI, can confirm data integrity.
• Non-repudiation: Provides undeniable proof of an action, such as sending a message or signing a document. A digital signature linked to a private key prevents a sender from denying they sent a message. This is discussed in publications like McCullagh and Caelli's "Non-repudiation in the digital environment" (http://www.firstmonday.dk/issues/issue5_8/mccullagh/index.html#author).

The concepts of public-key cryptography and PKI are fundamental to network security, as detailed in texts such as Joseph Migga Kizza's Guide to Computer Network Security (https://books.google.com.gh/books?id=sbA_AAAAQBAJ).