Described are techniques for security access and control. The techniques use a system that includes a card reader system including a processor and memory. The card reader system is configured to execute a security application that configures the card reader system to receive an embedded electronic credential from an access badge, with the embedded electronic credential carried by the access badge and being associated with a user, determine whether the credential indicates an authorized access, generate a message according to a result of the determination, and send the message to a distributed ledger that logs the result in the distributed ledger.