Internet Protocols (Cambridge International IGCSE ICT)

Protocols

What is a protocol?

• A protocol is a set of rules that govern communication on a network

• There are protocols for different purposes, some of them include:

  • HTTP & HTTPS
  • FTP
  • SSL & TLS
  • VoIP
  • SMTP

HTTP & HTTPS

What is HTTP & HTTPS?

• Hypertext Transfer Protocol (HTTP) allows communication between clients and servers for website viewing
• HTTP allows clients to receive data from the sever (fetching a webpage) and send data to the server (submitting a form, uploading a file)
• HTTPS works in the same way as HTTP but with an added layer of security. All data sent and received using HTTPS is encrypted
• HTTPS is used to protect sensitive information such as passwords, financial information and personal data

FTP

What is FTP?

• File Transfer Protocol (FTP) allows sending and receiving files between computers
• Uploading and downloading files to/from a web server is often completed using FTP
• FTP offers greater efficiency and support for bulk transfers and large files such as resuming interrupted transfers
• FTP clients are software applications that use the FTP protocol to make the process easier for users

SSL & TLS

What is SSL & TLS?

• Secure socket layer (SSL) is a security protocol developed to provide secure communication over the internet

• TLS is a successor to SSL and is also a security protocol used to provide secure communication over the internet

• They both use a combination of symmetric and asymmetric encryption to secure data and ensure data integrity

• SSL operates by encrypting a user's data using a public key

  • This is done by sending a digital certificate to the user’s browser
  • This contains the public key which can be used for authentication

Where is SSL used?

• SSL is used in a variety of situations where a secure connection is required, some examples of this include:

  • Online banking
  • Online shopping
  • Using cloud storage
  • Messaging
  • Social networking websites
  • Intranets/extranets

Worked Example Protocols are associated with the internet and an intranet.

Identify three protocols and for each one, identify a use. [6]

Final answer: Answers

Matched pairs:

HTTP/HyperText Transfer Protocol Transfer data between a webserver and the browser//display/loads pages//connect to a webpage [1]

Final answer: HTTPS/ HyperText Transfer Protocol Secure variant

One from: Transfer data between a webserver and the browser securely [1] Display/loads secure pages [1] Connect to a secure webpage [1] Secure variant of HTTP [1]

FTP/File Transfer Protocol Transfers files between computers/website [1]

SSL/TLS Determines variables of the encryption for both the link and the data being transmitted [1]