Digital-Signatures

Cryptography fundamentals for developers Data protection matters for apps, services, and users. Understanding a few fundamentals helps you choose safe patterns and avoid common mistakes. This guide uses plain language and practical tips you can apply today. Symmetric vs. asymmetric encryption Symmetric encryption uses one secret key to both encrypt and decrypt data. It is fast and suitable for large data. In practice you use a strong algorithm like AES with a modern mode such as GCM to get both confidentiality and integrity. Asymmetric encryption uses a pair of keys: a public key for encryption and a private key for decryption. It helps with key distribution and digital signatures, but it is slower. A typical setup combines both: encrypt data with a symmetric key, then protect that key with an asymmetric public key. ...

Cryptography Basics for Developers Cryptography helps protect information by transforming it. It can keep secrets safe, prove who sent a message, and ensure it wasn’t tampered with. As a developer, you should rely on proven libraries rather than writing crypto code yourself. Small mistakes can undermine security and give attackers an easy path in. What cryptography does Cryptography has three main jobs: confidentiality (keeping data secret), integrity (detecting tampering), and authenticity (proving who sent something). ...

Cryptography Essentials for Developers Cryptography helps protect data both at rest and in transit. As a developer, you don’t need to become a cryptography expert, but knowing a few basics helps you ship safer software. In simple terms, encryption turns plaintext into ciphertext using a key. Two common setups exist: symmetric encryption, which uses the same key to lock and unlock data, and asymmetric encryption, which uses a public key to encrypt and a private key to decrypt. Hashing creates a fixed, short fingerprint of data and is useful for integrity and password storage when used correctly. ...

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. ...