encrypted

Encrypted refers to data that has been transformed through an encryption process to conceal its content. In encryption, plaintext is converted into ciphertext using an algorithm and a key; without the key, the data should be unreadable. Decryption uses the key to recover the original plaintext. Encryption protects confidentiality during storage (data at rest) and transmission (data in transit) and is a foundational element of modern information security.

There are two main types of encryption: symmetric and asymmetric. In symmetric encryption, the same key is used to encrypt and decrypt, which is efficient for large data and common in disk encryption and TLS sessions with pre-shared keys. In asymmetric encryption, a public key encrypts and a private key decrypts, enabling secure key exchange and digital signatures; common examples include RSA and Elliptic Curve Cryptography (ECC). Hybrid systems combine both: a symmetric session key is encrypted with an asymmetric key.

Common algorithms include AES for symmetric encryption and RSA, ECC, or ElGamal for asymmetric encryption. Encryption modes such as AES-GCM provide confidentiality and integrity. Key management, proper implementation, and secure randomness are critical; weak keys, side-channel leaks, or flawed software can undermine security.

Applications include securing web traffic (TLS), email encryption (PGP/MIME), virtual private networks (VPNs), and full-disk encryption. The field faces evolving threats, including quantum computing, which drives the development of post-quantum cryptography and new standards for secure long-term data protection.