XMPP Security

Owned by Davood Sooran (Deactivated)
Last updated: Aug 29, 2024
4 min read

Security in MMS vs XMPP:

When evaluating the security elements between XMPP and MMS within network communication, several key considerations come into play:

XMPP Security:

    • Features: Robust security provisions like TLS and SASL.

    • Functionality: Provides end-to-end encryption and secure communication channels.

    • Authentication: Offers user authentication for secure connections.

MMS Security:

    • Native Form: Lacks inherent encryption or authentication mechanisms.

    • Implementation: Additional security measures like TLS can be integrated for channel security.

In summary, both XMPP and MMS, fortified with TLS, offer secure communication channels. Selection depends on application specifics, network architecture, and security needs. XMPP suits dynamic and decentralized setups, while MMS, with additional configurations, can attain similar security levels.


XMPP Security

XMPP, as defined in RFC 6120, prioritizes security features that address both client-side concerns and server communication. Illustrated in the figure 1, XMPP emphasizes a comprehensive security approach, integrating transport layer protection alongside XMPP peer authentication as core security measures.

This integrated security framework entails the combination of transport layer Security protocols, bolstering encryption and data integrity during transmission, with XMPP's inherent peer authentication mechanisms. Together, these measures fortify the overall security posture, ensuring robust protection for both client interactions and server communications within the XMPP framework.










Fig. 1: Security mechanisms in XMPP


Fig. 2 illustrates the XMPP communication connections, categorized into end-to-middle (E2M) transport layer connections and end-to-end (E2E) application layer connections. The E2M connections operate between XMPP client–server or server–server at the transport layers, while E2E connections are established between IEC 61850 client–server at the application layer, as depicted in Fig. 1. Consequently, security mechanisms are incorporated at both the transport and application layers for SCSM 8-2 mapping.
























Fig. 2: Communication flow sequence between XMPP clients


In E2M XMPP communication, mutual authentication, integrity, and confidentiality are attained at the transport layer through the implementation of two security protocols: TLS and SASL. Following the specifications outlined in RFC 6120 (XMPP Core), the TLS protocol is utilized to define an SSL/TLS profile, ensuring data encryption to prevent tampering and eavesdropping. As depicted in Fig. 2, between the XMPP client and XMPP server, a TCP connection is first established, and subsequently, a TLS connection is negotiated through the exchange of 'STARTTLS' commands and X.509 certificates. This TLS negotiation results in all transmissions becoming encrypted and secure, thereby ensuring integrity and confidentiality within E2M communication. Upon completion of TLS negotiation, SASL authentication messages are exchanged, validating the end peers as authenticated users for continued XMPP client–server communication.

The application layer's E2E security for IEC 61850 SCSM 8-2 relies on implementing MMS secure sessions utilizing the End-to-End Security Protocol (E2E SecProtocol) mechanism, in accordance with the guidelines set by IEC 62351-4. During the initiation, the IEC 61850 client and server engage in an exchange of E2ESecProtocol mapped "Handshake_request" and "Handshake_accept" messages, respectively. These initial messages serve the purpose of establishing an association by authenticating the endpoints, namely the IEC 61850 client and server.


Security Mechanisms in XMPP and MMS

The security mechanisms in XMPP and MMS (over IEC 61850) differ significantly in terms of implementation, focus, and the layers at which they operate:

  1. XMPP:

    • Transport-Level Security: Uses mechanisms like Transport Layer Security (TLS) and Secure Sockets Layer (SSL) to encrypt communications between clients and servers. TLS/SSL secures the connection itself, ensuring data confidentiality and integrity during transmission.

    • End-to-End Encryption: Offers extensions such as OTR (Off-the-Record Messaging) or OMEMO (OMEMO Multi-End Message and Object Encryption) for end-to-end encryption, securing conversations between users.

  2. MMS in IEC 61850:

    • Higher-Layer Security: MMS, as a messaging specification for industrial applications, doesn't inherently include specific encryption mechanisms but relies on higher-layer security protocols.

    • Integration with Network-Level Security: Often integrates with broader network security protocols such as IPsec (Internet Protocol Security) or TLS at the network layer to ensure secure communication between devices or systems.

  3. Focus of Security:

    • XMPP: Focuses on securing real-time messaging and presence information primarily for instant messaging and related applications. Provides a combination of transport-level security and end-to-end encryption.

    • MMS in IEC 61850: Concentrates on messaging within industrial automation contexts, transmitting control and monitoring data. While not specifying encryption itself, it often relies on network-level security protocols for secure data transmission in industrial settings.

  4. Use Cases and Contexts:

    • XMPP: Widely used in instant messaging, social networking, and communication applications where real-time data exchange and user privacy are key concerns.

    • MMS in IEC 61850: Applied within industrial automation and control systems where the focus is on secure and reliable transmission of data related to control, monitoring, and management of industrial processes.

In summary, while both XMPP and MMS (IEC 61850) emphasize secure communication, XMPP typically implements encryption mechanisms at the application and transport layers, focusing on real-time messaging and end-to-end encryption. MMS in IEC 61850 relies more on broader network-level security protocols for securing data transmission within industrial automation contexts.


Which one to consider?

Choosing between XMPP and MMS for use within IEC 61850 largely depends on the specific requirements and context of the industrial automation system:

Consider XMPP If:

    • Real-Time Messaging is Crucial: If your application involves real-time messaging, presence information, or requires instant communication capabilities, XMPP might be a suitable choice.

    • Need for End-to-End Encryption: If ensuring end-to-end encryption for communication between devices is a priority, XMPP offers specific extensions like OMEMO or OTR for this purpose.

Consider MMS within IEC 61850 If:

    • Industrial Automation Requirements: MMS is more aligned with the standards and requirements of industrial automation and control systems. If your focus is on control, monitoring, and management within industrial contexts, MMS might be a more natural fit.

    • Integration with Existing Protocols: If your infrastructure already heavily relies on IEC 61850 or related protocols within the industrial domain, integrating MMS might be more seamless.

Ultimately, the choice between XMPP and MMS for IEC 61850 depends on the specific needs of the industrial application. Both have their strengths: XMPP for real-time messaging and end-to-end encryption, and MMS for its alignment with industrial automation standards. Assessing the specific requirements and compatibility with existing systems will guide the selection process.