nyckelpar

Nyckelpar is the term for a pair of cryptographic keys used in asymmetric cryptography, consisting of a public key and a private key that are mathematically linked. The public key is shared openly and is used to encrypt data or verify digital signatures, while the private key remains secret and is used to decrypt data or create signatures. This arrangement enables secure communication without a pre-shared secret.

Key generation for a nyckelpar is performed by a key generation algorithm tied to a specific cryptographic scheme, such as RSA, Elliptic Curve Cryptography (ECC), or Ed25519. The process produces two related keys: the public key, which can be distributed widely, and the private key, which must be protected. In RSA, keys are large integers derived from primes; in ECC-based schemes, the keys relate to a point on an elliptic curve. The public key is derived from the private key, but the private key cannot be feasibly determined from the public key.

Usage scenarios include encryption, digital signatures, and authentication. In encryption, someone with the public key can encrypt a message that only the corresponding private key can decrypt. In digital signatures, the private key signs a message or its hash, and others verify the signature using the public key. Nyckelpar are fundamental to protocols such as TLS for web security, SSH for remote access, and PGP for email.

Security and management involve protecting the private key from leakage, choosing appropriate algorithms and key lengths, and employing secure storage such as hardware security modules or encrypted wallets. Practices include key rotation, revocation, and proper key lifecycle management to maintain trust in the associated identities or services.