Cryptography

Quantum-Safe Cryptography: Preparing for the Post-Quantum World Quantum computers are not just a theory anymore. They could break common public key systems that protect web traffic, email, and software updates. This risk matters for data that must stay secure for many years. The good news is that researchers have quantum-safe methods ready today. With practical planning, organizations can prepare for a post-quantum world. Quantum-safe means choosing algorithms that resist quantum attacks. The main families are lattice-based, hash-based, code-based, and multivariate schemes. Lattice-based options often balance security with good performance; hash-based signatures are simple and robust; code-based methods offer strong long-term security. A practical plan uses more than one family to cover different tasks, from encrypting messages to signing software. ...

Cryptography Essentials for Practitioners Cryptography helps protect data in motion and at rest. For practitioners, the goal is to apply solid, proven choices consistently rather than chase every new gadget. Start with three goals: confidentiality, integrity, and authenticity. These map to encryption, hashes, and signatures, but real systems mix them across layers. Core ideas you should know include the following. Use symmetric encryption for fast confidentiality, such as AES-256 in GCM mode, with a unique nonce for each message. For key exchange and identity, rely on asymmetric schemes like ECC or RSA and prefer modern signatures such as EdDSA or ECDSA. Hash functions like SHA-256 or SHA-3 support integrity, and with a keyed MAC you gain strong authenticity. Key derivation and randomness matter: HKDF helps derive keys safely, and cryptographically strong random numbers are essential for nonces, salts, and keys. Always prefer authenticated encryption, which provides both secrecy and integrity in one step. ...