File transfer: SFTP MCQs Quiz | Class 10

This quiz on File transfer: SFTP for Class X Computer Applications (Code 165), Unit 1: Networking, tests your understanding of secure file transfer over SSH. Attempt all 10 multiple-choice questions, submit your answers, and then download a detailed PDF answer sheet for review.

Understanding SFTP and Secure File Transfer

File Transfer Protocol (FTP) has long been the standard for moving files between computers over a network. However, traditional FTP lacks crucial security features, leaving data vulnerable during transfer. This is where SFTP comes in, providing a robust and secure alternative.

What is SFTP?

SFTP stands for Secure File Transfer Protocol. Despite its name, it is not simply FTP over SSL/TLS (which is FTPS). Instead, SFTP is an entirely separate file transfer protocol that functions as a subsystem of the Secure Shell (SSH) protocol. It provides a secure way to access, transfer, and manage files on remote systems.

How SFTP Uses SSH for Security

The core of SFTP’s security lies in its reliance on SSH (Secure Shell). SSH provides a secure channel over an unsecured network by encrypting the entire session. When SFTP operates over SSH, it inherits the following security benefits:

  • Encryption: All data, including usernames, passwords, commands, and the files themselves, are encrypted during transfer. This prevents eavesdropping and ensures confidentiality.
  • Authentication: SSH provides strong authentication mechanisms, typically using passwords or SSH keys (public-private key pairs). This verifies the identity of both the client and the server, preventing unauthorized access.
  • Data Integrity: SSH ensures that data is not tampered with during transmission. If any data is altered, it will be detected, and the connection will be dropped.
  • Port Usage: SFTP typically uses port 22, the standard port for SSH, unlike FTP which uses ports 20 and 21.

SFTP vs. FTP vs. FTPS: A Comparison

It’s important to differentiate between these three common file transfer methods:

Feature FTP (File Transfer Protocol) SFTP (SSH File Transfer Protocol) FTPS (FTP Secure)
Security Mechanism None (plaintext) SSH (Secure Shell) SSL/TLS (Secure Sockets Layer/Transport Layer Security)
Encryption No Yes (entire session) Yes (data and/or control channel)
Port(s) Used 20 (data), 21 (control) 22 (standard SSH port) 21 (control), variable (data)
Underlying Protocol FTP SSH FTP
Firewall Friendliness Challenging (multiple ports) Easier (single port 22) Challenging (multiple ports, dynamic)

In summary, SFTP is generally preferred for its robust, single-port security, making it easier to manage in firewall environments and providing comprehensive encryption for the entire session.

Common SFTP Operations

SFTP clients (graphical or command-line) offer various commands to interact with remote file systems:

  • sftp user@hostname: Initiates an SFTP connection.
  • ls: Lists files and directories on the remote server.
  • cd directory_name: Changes the current directory on the remote server.
  • lcd directory_name: Changes the current directory on the local machine.
  • put local_file: Uploads a file from the local machine to the remote server.
  • get remote_file: Downloads a file from the remote server to the local machine.
  • rm remote_file: Deletes a file on the remote server.
  • mkdir new_directory: Creates a new directory on the remote server.

Quick Revision Points

  • SFTP means Secure File Transfer Protocol.
  • It operates over the SSH protocol, ensuring encryption and authentication.
  • SFTP typically uses port 22.
  • It provides confidentiality, integrity, and strong authentication.
  • SFTP is not an extension of FTP; it’s a separate, more secure protocol.
  • Unlike FTP, SFTP encrypts both data and control information.
  • SSH keys can be used for passwordless and more secure authentication in SFTP.

Extra Practice Questions

  1. Which of the following is the primary reason to use SFTP instead of traditional FTP?
    1. Faster transfer speeds
    2. Encrypted communication
    3. Simpler client software
    4. Wider port compatibility
  2. SFTP uses which underlying protocol for secure communication?
    1. HTTP
    2. SMTP
    3. SSH
    4. TCP/IP
  3. What is the default port commonly associated with SFTP?
    1. 80
    2. 21
    3. 443
    4. 22
  4. Which SFTP command is used to upload a file from your local computer to the remote server?
    1. download
    2. put
    3. get
    4. send
  5. Is SFTP an older version of FTP?
    1. Yes, it’s the original FTP.
    2. No, it’s a completely different protocol built on SSH.
    3. It’s FTP with a different encryption method.
    4. It’s only used for very large files.