Public key infrastructure.

Sample Solution

What is a PKI? A PKI is a system that uses a set of digital certificates to authenticate and secure communications. It is used in a variety of applications, including secure web browsing, email encryption, and electronic signatures. Major components of a PKI The major components of a PKI are:

• Root CA: The root CA is the highest authority in the PKI. It is responsible for issuing certificates to other CAs.
• CAs: CAs are responsible for issuing certificates to users and devices. They are trusted by the root CA.
• Digital certificates: Digital certificates are electronic documents that contain the public key of a user or device. They also contain information about the user or device, such as their name and email address.
• Registration authorities (RAs): RAs are responsible for verifying the identity of users and devices before they are issued a digital certificate.

How does a PKI work? When two parties want to communicate securely, they first need to exchange their digital certificates. This allows them to verify each other's identity. Once they have verified each other's identity, they can use the public keys in their digital certificates to encrypt their communications. Why can an active attacker break an SSL connection, but not an IPsec connection? An SSL connection can be broken by an active attacker because SSL is a symmetric encryption protocol. This means that the same key is used to encrypt and decrypt the data. If an attacker can intercept the key, they can decrypt the data. IPsec is an asymmetric encryption protocol. This means that there are two keys, a public key and a private key. The public key is used to encrypt the data, and the private key is used to decrypt the data. If an attacker intercepts the public key, they cannot decrypt the data because they do not have the private key. In addition, IPsec uses a variety of security features to protect the data, such as authentication, integrity, and confidentiality. These features make it more difficult for an attacker to break an IPsec connection.