Cryptography, Blockchain, & Cybersecurity Study Guide

Flashcards for review.

Hash Functions

One-way, deterministic, fixed-length output used for passwords, data integrity, digital signatures, and blockchain.

Pre-image resistance

A property of hash functions that makes it hard to find an input that produces a specific hash output.

Collision resistance

A property of hash functions that makes it hard to find two different inputs that produce the same hash output.

Rainbow Tables

An attack on password hasing that can be defeated by salting.

One-Time Pad (OTP)

A symmetric cipher that provides perfect secrecy if used correctly; vulnerable if the key is reused.

Stream Cipher

A symmetric cipher based on a Pseudo-Random Generator (PRG); secure if the PRG is unpredictable.

Block Ciphers

Ciphers that encrypt data in fixed-size blocks.

Data Encryption Standard (DES)

A 64-bit block cipher using a 56-bit key and a Feistel network.

Advanced Encryption Standard (AES)

A modern symmetric encryption standard with 128/192/256-bit keys.

Electronic Codebook (ECB)

A block cipher mode that is insecure and deterministic.

Cipher Block Chaining (CBC)

A block cipher mode that uses an Initialization Vector (IV) and is good for confidentiality.

Counter (CTR)

A block cipher mode that turns a block cipher into a stream cipher.

RSA

An asymmetric encryption algorithm.

Diffie-Hellman Key Exchange

A key exchange protocol that allows two parties to establish a shared secret key over an insecure channel.

Entropy

A measure of randomness; high entropy leads to more randomness.

Secure PRNG

Unpredictable, deterministic, seeded from entropy and has no bias.

Blockchain

A data structure consisting of blocks, where each block contains data, a timestamp, the previous hash, and a nonce.

Proof of Work (PoW)

A consensus mechanism that is energy-intensive and uses hash puzzles.

Ripple Protocol Consensus Algorithm (RPCA)

A consensus mechanism where Unique Node Lists (UNLs) vote in rounds, requiring 80% agreement.

Message Authentication Code (MAC)

Provides integrity and authentication.

CBC-MAC

Message Authentication Code based on Cipher Block Chaining, not secure for variable-length messages.

CMAC

A secure MAC that uses a separate key for the last block.

Vulnerability Management Lifecycle

Discovery → Assessment → Prioritization → Remediation → Verification.

Weak AI

Also known as Machine Learning (ML).

Biometrics

Security mechanism using fingerprint scanners or other methods. Use MFA, educate users, gain consent, encrypt biometric data.

Maritime Cybersecurity Threats

GPS spoofing/jamming, Bridge system hijacking, Ransomware at ports, Compromised supply chains.