Tanúsítványlánc

tanúsítványlánc, meaning "certificate chain" in Hungarian, refers to a hierarchical structure of digital certificates used in cryptography to establish trust. It begins with a root certificate, which is self-signed and trusted by operating systems and browsers. This root certificate then vouches for an intermediate certificate, which in turn vouches for another intermediate certificate, and so on, until it reaches the end-entity certificate. The end-entity certificate is typically issued to a specific entity, such as a website or an individual, and is used to verify their identity and secure communications.

When a user's device encounters an end-entity certificate, it traverses the certificate chain upwards towards the root. Each certificate in the chain is digitally signed by the certificate that precedes it. By verifying these signatures sequentially, the device can confirm the authenticity of the end-entity certificate. If any certificate in the chain is invalid, expired, or has been revoked, the trust cannot be established, and a warning is typically displayed to the user.

The purpose of a certificate chain is to distribute trust from a few highly trusted root authorities to a vast number of end-entity certificates. This hierarchical model allows for scalability and efficient management of digital certificates. It is a fundamental component of Public Key Infrastructure (PKI) and is essential for secure internet browsing, email communication, and various other digital security applications. The integrity of the entire chain is paramount; a compromise at any level can weaken or break the trust model.