SNMP version 3 supports secure communication. Unlike SNMP v1 and v2, it uses username/password authentication and SSL encryption.
SNMP version 3 is designed for secure management of networks with many devices. Typical applications include infrastructure monitoring (including the signal quality of microwave links, disk space on servers, battery states in UPS units, etc.).
Related: SNMP v1 / v2
In the context of NETIO products
In the context of NETIO products, all NETIO 4x products support reading as well as control over SNMP v3.
NETIO specification of the SNMP M2M protocol: Download page