Create Your Own Self Signed X509 Certificate

X.509 certificates are digital documents that represent a user, computer, service, or device. They are issued by a certification authority (CA), subordinate CA, or registration authority and contain the public key of the certificate subject. They do not contain the subject's private key which must be stored securely.

Tutorial: Understanding X.509 Public Key Certificates

X.509 Digital Signature Signing (In C#)

X.509 Digital Signature Validating (In C#)