Rogue Security Wiki

Study notes covering Cryptography.

Terminology

Term Definition
Hash One-way function that creates a fixed-length output from variable input
Cipher Algorithm used for encryption/decryption
Encryption Process of converting plaintext into unreadable ciphertext
Symmetric Cryptography Uses a single shared key for encryption and decryption (fast, but key distribution is hard)
Asymmetric Cryptography Uses a public/private key pair (slower, but solves key distribution)
HSM (Hardware Security Module) Dedicated device for secure key storage and cryptographic operations
TPM (Trusted Platform Module) Hardware chip that provides secure key storage and system integrity checks
BitLocker Windows feature for full-disk encryption
EFS (Encrypting File System) Windows feature for file-level encryption
RSA Asymmetric algorithm, widely used for key exchange and digital signatures
AES Symmetric algorithm, standard for encrypting data (fast, secure)
ECC (Elliptic Curve Cryptography) Asymmetric algorithm offering strong security with smaller key sizes
Diffie–Hellman Key exchange protocol for securely establishing a shared key
Hashing Converts data into a fixed-length digest; used for integrity, not confidentiality
MD5 Hash algorithm, now broken and insecure
SHA-1 Hash algorithm, deprecated due to weaknesses
SHA-256 Secure hash algorithm, widely used today
PKI (Public Key Infrastructure) System of CAs, certificates, and keys enabling secure communications
Digital Signature Proves authenticity and integrity using hashing + asymmetric keys
Steganography Hiding data within another file (e.g., image, audio)
SSL Legacy protocol for secure web traffic (deprecated)
TLS Modern protocol replacing SSL for secure communications
Certificates Digital documents binding an identity to a public key
PGP (Pretty Good Privacy) Encryption software for email and files
GPG (GNU Privacy Guard) Open-source implementation of PGP

🗄️ Data at Rest


🌐 Data in Transit


🔑 Public Key Infrastructure (PKI)


✍️ Digital Signatures


📌 Common Algorithms & Use Cases

Type Algorithm Common Use
Symmetric AES, DES, 3DES Encrypting files, VPN tunnels, BitLocker
Asymmetric RSA, ECC Digital signatures, certificate-based logins, key exchange
Hashing SHA-256, SHA-3 Password storage, digital signatures, file integrity