What is a Sub CA?
A Sub CA is a Certification Authority whose certificate has been signed by a higher-level CA. Depending on the PKI structure, it can issue certificates for additional subordinate CAs or end-entity certificates for users, devices, servers, and applications.
What is a Root CA?
The Root CA is the highest trust authority in a hierarchical PKI. Its certificate is self-signed and serves as the trust anchor for the Certification Authorities below it. Because the Root CA’s private key requires a particularly high level of protection, the Root CA is often operated offline in environments with high security requirements and […]
What are the components of a PKI?
The central components of a PKI include Certification Authorities (CAs), Registration Authorities (RAs) where applicable, digital certificates, revocation information, as well as policies and processes for issuing, managing, renewing, and revoking certificates. The CA structure often consists of a Root CA and one or more subordinate CAs.
What is a digital signature?
A digital signature is created using a private key and can be verified using the corresponding public key. This makes it possible to determine whether the signed data has been modified since it was signed and whether the signature was created using the corresponding private key.
What does a digital certificate confirm?
A digital certificate confirms the association of a public key with a specific identity or entity. Depending on the certificate, this may be a person, device, server, application, or organization.
What is an X.509 certificate?
An X.509 certificate is a standardized digital certificate that associates a public key with an identity. Among other things, it contains information about the certificate holder, the public key, the issuing Certification Authority, the validity period, and the intended purposes of the certificate.
What role do certificates play in a PKI?
Digital certificates are a central component of a PKI. They associate a public key with a specific identity, such as a person, server, application, or device. The Certification Authority confirms this association using its digital signature.
What is the difference between Public Key Cryptography and PKI?
Public Key Cryptography refers to cryptographic methods that use public and private keys. A PKI adds a trust infrastructure consisting of certification authorities, certificates, policies, and processes. This allows public keys to be reliably associated with identities and securely managed even in large IT environments.
How does Public Key Cryptography work?
Public Key Cryptography uses a mathematically related key pair: a public key and a private key. The private key remains secret, while the public key can be distributed. Depending on the cryptographic method, the key pair can be used, for example, to encrypt data or to create and verify digital signatures. The private key is […]
Why is a PKI needed?
A PKI is needed to reliably associate public keys with specific identities and to provide trusted proof of that association. This makes it possible to securely authenticate people, devices, servers, and applications and to protect digital communications.