Cisco Certified Network Associate (CCNA) Practice Exam

What protocol is used to secure communications over the Internet at the application layer?

1. Transport Layer Security (TLS)

2. Internet Protocol Security (IPSec)

3. Secure Socket Layer (SSL)

4. Hypertext Transfer Protocol Secure (HTTPS)

The correct answer is: Secure Socket Layer (SSL)

The correct answer focuses on how secure communications are established at the application layer. Hypertext Transfer Protocol Secure (HTTPS) is essentially HTTP layered over Transport Layer Security (TLS) or, in older implementations, Secure Socket Layer (SSL). It provides a secure communication channel between the web server and the client's browser, which is crucial for protecting sensitive data such as personal information and credit card details during online transactions. While SSL is indeed used for secure communications, it is now largely obsolete and replaced by TLS, which is a more secure version of the protocol. Nevertheless, when referring specifically to application-layer security in the context of web communications, HTTPS is the most accurate answer because it directly signifies the secure use of HTTP. Transport Layer Security (TLS) is vital as well, but when considering the application layer, HTTPS operates at a higher level by employing TLS to enhance the security of web traffic. Internet Protocol Security (IPSec) functions at the network layer and is not specific to application-layer communications, so it does not fit the question's requirement.