Block Ciphers Modes of Operation Quiz

Asymmetric Encryption

• Asymmetric encryption uses different keys for encryption and decryption.

Caesar Cipher

• Caesar Cipher replaces each character with another character a fixed number of positions down the alphabet.

Advanced Encryption Standard (AES)

• AES stands for Advanced Encryption Standard in the context of cryptography.

Differential Attack

• Differential attack analyzes how differences in input can affect the resulting encrypted output.

One-Time Pad (OTP)

• For a One-Time Pad (OTP) to be secure, the key must be at least as long as the plaintext, never reused, and kept secret.

Block Cipher

• Block Cipher operates on fixed-size blocks of data, rather than manipulating individual characters.

AES ShiftRows and ShiftColumns

• AES ShiftRows and shiftColumns step ensures the mixing of columns and diffusion of rows.

Linear Cryptanalysis

• The main focus of Linear Cryptanalysis is on finding linear approximations of the block cipher's nonlinear components, such as S-boxes, in block ciphers like DES, 3DES, and AES.

Differential Cryptanalysis

• Differential Cryptanalysis studies how pairs of inputs with a fixed difference in plaintext produce a fixed difference in ciphertext in relation to block ciphers.

Cryptographic Hash Function (CHF)

• A Cryptographic Hash Function (CHF) feature is that it is deterministic, non-invertible, and collision-resistant.

SHA-256

• In Cryptographic Hash Function SHA-256, 'SHA' stands for Secure Hash Algorithm.

MixColumns in AES

• The primary goal of MixColumns in AES, in conjunction with ShiftRows, is to ensure diffusion of columns.

ECB and CBC Modes

• The main difference between ECB and CBC modes of operation in block ciphers is that ECB does not use an initialization vector (IV), while CBC does.

NIST and AES

• The National Institute of Standards and Technology (NIST) replaced DES with AES as the standard encryption algorithm due to DES's vulnerability to brute-force attacks.

ECB Mode

• ECB mode of operation in block ciphers results in identical ciphertext blocks when encrypting identical plaintext blocks with the same key.

DES Cracking

• Cracking the DES algorithm was made possible in the 1990s due to its small key size, making it vulnerable to brute-force attacks.

CBC Mode

• CBC mode of operation in block ciphers partially depends on adjacent blocks during encryption.

DES Original Practicality

• DES was originally practical only in hardware implementations because its computational requirements were too high for software implementations at the time.

Test your knowledge on various modes of operation in block ciphers such as ECB, CBC, and CTR. Understand how different methods combine block operations for encryption and decryption, and the characteristics of Electronic Code Book mode.