Avalikvõtmega

Avalikvõtmega, or public key, is a fundamental concept in asymmetric cryptography. It is one part of a pair of mathematically related keys used for secure communication and digital signatures. The public key can be freely distributed and is used to encrypt messages intended for the owner of the corresponding private key, or to verify the authenticity of a digital signature created by the private key.

The strength of public-key cryptography lies in the fact that while the public key can be known by anyone, it is computationally infeasible to derive the private key from it. This asymmetry is what enables secure transactions and communications over insecure channels like the internet. For instance, when you send a secure message to a website, your browser uses the website's public key to encrypt the data. Only the website, with its corresponding private key, can decrypt and read the message.

Digital signatures utilize public keys in the reverse manner. An individual uses their private key to create a unique digital signature for a document. Anyone can then use the sender's public key to verify that the signature is valid and that the document has not been tampered with since it was signed. This process ensures both the authenticity and integrity of digital information. Public key infrastructure (PKI) systems are built around managing and distributing these public keys securely, often through digital certificates.