Multilayer and Converged Protocols
Multilayer and converged protocols integrate diverse communication layers, streamlining data exchange while demanding careful design to maintain performance, compatibility, and security.
2 slides · 2 min read · Domain 4
While general communications infrastructures rely heavily on the Transmission Control Protocol/Internet Protocol (TCP/IP) suite, many protocols exist to meet the demands of specific environments or are proprietary to an organization.
However, the advantages of the broad adoption of the TCP/IP suite are somewhat attractive when attempting to connect infrastructures or reduce the cost of dedicated networks. Consequently, many of these protocols can be configured for TCP/ IP to carry the protocol as a data payload.
This opens the possibility that the combination of protocols may create a larger attack surface, or that the TCP/IP suite will not offer the quality of service (QoS) needed by an application. This is particularly troubling in the critical infrastructure environments where there are life-safety implications to the communications between the devices.
For example, the Modbus protocol is widely used in supervisory control and data acquisition (SCADA) infrastructures, such as refineries, petroleum pipelines, electrical power distribution, and other critical infrastructure networks. Modbus does not include any authentication mechanism and has no cryptographic protection for information being passed; as a result, it has proved vulnerable to denial-of-service attacks. Modbus protocols have been able to use the TCP/IP protocols for transport for almost 20 years. However, with the exception of limited integrity protections, the other security issues remained unaddressed until 2018 with the adoption of Transport Layer Security (TLS) to provide confidentiality and authenticity protections to data.
Other protocols, in such areas as telecommunications and healthcare, present similar challenges to providing secure connectivity between devices.
While industries develop new protocols and technologies, the existence of legacy devices will significantly delay the transition to more secure methods of communication.
Many of these situations involve the use of converged protocols, in which standard protocols (such as TCP/IP) are combined (or converged) with proprietary or other nonstandard protocols. These can sometimes provide greatly enhanced functionality and security to meet the needs of specific situations or industries. However, they can complicate enterprise-wide security engineering efforts by requiring additional specialist knowledge and skills to manage and secure.