encryptions

Encryption is a method of protecting information by transforming it into an unreadable form unless one has the key. It is a core part of cryptography. The reverse process is decryption. It can protect data in transit or at rest. It relies on algorithms and keys; the strength depends on the algorithm, key length, and proper implementation.

Symmetric-key encryption uses a single shared key for encryption and decryption. It is fast and suitable for large data. Common algorithms include AES, DES, 3DES, and ChaCha20. Modes of operation like CBC, CFB, CTR, and GCM provide different properties; authenticity often requires an authentication tag (AEAD modes such as AES-GCM). Key management is critical, as the same key must remain secret between communicating parties.

Asymmetric, or public-key encryption, uses a pair of mathematically linked keys: a public key for encryption and a private key for decryption. Algorithms include RSA, DSA, and elliptic-curve variants such as ECDSA for signatures and ECDH for key exchange. Public-key cryptography enables secure key exchange and digital signatures and is widely used in protocols such as TLS.

Applications and properties: encryptions aim to provide confidentiality; integrity and authentication are provided by additional mechanisms or authenticated encryption. End-to-end encryption ensures only end users can read messages. Encryption at rest protects stored data. Standards and compliance frameworks exist (NIST guidelines, FIPS). Weaknesses stem from weak algorithms, improper key management, or implementation flaws.

Challenges and future: quantum computers threaten some public-key schemes; post-quantum cryptography research is ongoing. The security of encryptions also depends on secure random number generation and resistance to side-channel attacks, emphasizing the need for up-to-date, well-implemented systems.