This paper proposes a communication cybersecurity architecture for smart distribution system operations using distributed network protocol (DNP3). The focus is on providing cybersecurity for residential load-management devices that are networked for access by the utility and their consumers. The proposed architecture utilizes DNP3 to produce a disjoint protocol between strictly-regulated utility devices and devices accessible by the utility and consumers. The disjoint protocol limits the effectiveness of attacks originated from the consumer TCP/IP access to a device into the utility network. Since DNP3 does not provide sufficient security, security enhancements to DNP3 are proposed using data object security and a security layer. The data object security provides data access rules to a device, preventing unauthorized manipulation of device operations and data. The security layer provides confidentiality through encryption between devices for consumer personal privacy and to prevent cyber-attackers from identifying potential utility targets.