Final answer:
The ITU standard for digital certificates is X.509, which is an integral component of the PKI system responsible for managing certificates and public-key encryption for secure electronic communication.
Step-by-step explanation:
The International Telecommunications Union (ITU) standard that governs the creation and endorsement of digital certificates for secure electronic communication is X.509.
X.509 is a crucial part of the Public Key Infrastructure (PKI) which is used to manage digital certificates and public-key encryption. It sets out standards for the format of public key certificates and includes specifications for the certificate's issuance and management by a certification authority (CA).
These digital certificates are used widely across various secure online transactions such as SSL/TLS, which provides security for web browsers and servers, and S/MIME for secure email communication.