Cryptography & Encryption II Flashcards
A random or pseudo-random value used in cryptographic algorithms to ensure that the same plaintext encrypted multiple times with the same key will result in different ciphertexts. It enhances security by preventing pattern recognition in the encrypted data.
In AES encryption, this is used alongside the encryption key to protect the data from predictable patterns, ensuring the ciphertext is different each time.
Initialization Vector (IV)
A mode of encryption that uses an IV (Initialization Vector) and combines each plaintext block with the previous ciphertext block before encrypting it. This makes the ciphertext dependent on all previous blocks, ensuring patterns are not easily discernible.
Each block of plaintext is XORed with the previous ciphertext block before being encrypted, making it more secure against certain attacks.
CBC (Cipher Block Chaining)
An encryption mode that combines the features of counter mode (CTR) and authentication, providing both data confidentiality and integrity. It uses an IV and generates a unique “authentication tag” to protect against tampering.
widely used in protocols like TLS (Transport Layer Security) to securely transmit data over the internet, as it ensures both encryption and message authenticity.
GCM (Galois/Counter Mode)
A mode of encryption that turns a block cipher into a self-synchronizing stream cipher by using feedback from the previous ciphertext block to encrypt the next block of plaintext.
CFB (Cipher Feedback)
A binary operation that outputs true (1) when the two input bits are different, and false (0) when they are the same. It is widely used in cryptography and error detection because it is reversible—applying this binary operation twice with the same key restores the original data.
In encryption, it is used to combine plaintext with a key to produce ciphertext.
XOR (Exclusive OR)
An encryption mode that uses a counter (a value that is incremented with each block) in combination with a key to generate a stream of “keystream” blocks, which are then XORed with the plaintext to produce ciphertext. It turns a block cipher into a stream cipher.
CTR (Counter Mode)
A mode that combines Counter Mode (CTR) for encryption with CBC-MAC (Cipher Block Chaining Message Authentication Code) for integrity and authentication. It provides both confidentiality and message integrity in a single operation.
Used in secure communication protocols like IPsec to both encrypt the data and verify its integrity.
CTM (Counter with CBC-MAC)
A simple encryption mode in which each block of plaintext is encrypted independently using the same encryption key. While easy to implement, this encryption has significant security weaknesses because identical plaintext blocks produce identical ciphertext blocks, potentially exposing patterns in the data.
If a message contains repetitive data (like a string of “AAAA”), the encrypted ciphertext will also have repeating patterns, making it vulnerable to analysis by attackers.
ECB (Electronic Codebook)
Refers to the length of the cryptographic key used in encryption algorithms, typically measured in bits. A larger key size generally provides stronger security, as it increases the number of possible key combinations, making brute-force attacks more difficult.
In AES (Advanced Encryption Standard), these can range from 128, 192, or 256 bits are commonly used.
Key Size (or Key Length)
An integrated circuit that combines all the components of a computer or electronic system on a single chip, including the CPU, memory, input/output ports, and often a graphics processor (GPU). It is commonly used in mobile devices, embedded systems, and IoT devices.
A smartphone uses this to combine its processor, graphics, and memory into a single chip
SoC (System on a Chip)
A modern type of firmware that initializes hardware during the boot process and provides a user interface to configure system settings. It replaces the older BIOS (Basic Input/Output System) and supports larger storage devices, faster boot times, and better security features.
Includes security features like Secure Boot, which prevents the loading of unauthorized operating systems or bootloaders
UEFI (Unified Extensible Firmware Interface)
A feature in Microsoft Windows that allows users to encrypt individual files or folders to protect sensitive data on a file system. It uses public key cryptography to ensure that only authorized users can decrypt and access the files.
Used by businesses to secure sensitive information stored on company devices,
EFS (Encrypting File System)
A physical device that generates, stores, and manages cryptographic keys. It is used to provide a high level of security for cryptographic operations, including key generation, encryption, and decryption, often used in industries that require secure data handling and compliance.
Secure the private keys used in digital signatures
HSM (Hardware Security Module)
A tool in Microsoft Windows that scans and repairs corrupted or missing system files that could cause system instability or performance issues. It uses a specific command to verify the integrity of protected system files and replace incorrect versions.
SFC (System File Checker)
A hardware-based security solution embedded into a computer’s motherboard that securely stores cryptographic keys, passwords, and certificates. It is used to protect sensitive information and enhance the security of the system by supporting functions like full disk encryption, secure boot, and hardware-based authentication.
used to store encryption keys for BitLocker, enabling full disk encryption in Windows.
TPM (Trusted Platform Module)
