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<rfc category="std" docName="draft-si-service-mesh-dta-01" ipr="trust200902">
  <front>
    <title>Dynamic Trust Security Architecture for Distributed Service
    Mesh</title>

    <author fullname="Xuan Si" initials="X" surname="Si">
      <organization>China Telecom</organization>

      <address>
        <postal>
          <street>Kangqiao Town, Pudong New District</street>

          <city>Shanghai</city>

          <region>Shanghai</region>

          <code>201315</code>

          <country>China</country>
        </postal>

        <email>six1@chinatelecom.cn</email>
      </address>
    </author>

    <date day="3" month="March" year="2025"/>

    <area>Service Mesh</area>

    <keyword>Internet-Darft</keyword>

    <abstract>
      <t>This document proposes a dynamic trust security architecture based on
      Distributed Micro Service Communication (DMSC) to address the security
      risks in the communication of microservices. The DMSC architecture, by
      leveraging content semantic routing and decentralized control,
      transforms the traditional host-centric communication mode into a
      service-centric paradigm. Although DMSC enhances scalability and
      flexibility, its distributed nature introduces risks. To cope with these
      risks, it is necessary to consider security solutions for distributed
      large-scale microservice communication and ensure the security of
      services while minimizing the impact on the communication
      architecture.</t>
    </abstract>
  </front>

  <middle>
    <section anchor="intro" title="Introduction">
      <t>1)Dynamic Service Instances Challenge Traditional Trust Models</t>

      <t>In DMSC<xref target="I-D.li-dmsc-architecture"/>, the traditional
      static trust models relying on IP/port-based mechanisms (e.g., firewall
      rules, VPN allowlists) struggle to maintain effective policies during
      service scaling or failover events, resulting in over-privileged access
      or service disruptions. Perimeter-centric defenses fail to adapt to the
      dynamic topology of east-west traffic between services.</t>

      <t>2)Tampering of Service Prefix Authentication (SPA)</t>

      <t>In the DMSC, SPA is used to verify the legitimacy of the service
      prefixes declared by the Pods to which microservices belong. Tampering
      attacks refer to attackers maliciously modifying, forging, or
      interfering with the authentication information during the SPA process.
      For example, an attacker may tamper with the service prefix to make an
      originally illegal service prefix appear legitimate, thus bypassing the
      authentication mechanism and obtaining unauthorized access rights. This
      may lead to the infiltration of illegal service instances into the
      system, undermining the security and integrity of services, affecting
      normal service communication and data interaction, and may even trigger
      serious consequences such as data leakage and service outages.</t>

      <t>3)Service Route Hijacking and Traffic Redirection</t>

      <t>Unauthorized microservices, taking advantage of weak access controls,
      may initiate lateral attacks. For instance, they could attempt to access
      sensitive data stored within other microservices, manipulate service
      configurations, or disrupt normal service operations. This not only
      undermines the security and integrity of individual microservices but
      also has the potential to spread across the entire microservice
      ecosystem. Weak access controls might allow these unauthorized
      microservices to bypass authentication and authorization mechanisms,
      enabling them to perform actions they are not supposed to. As a result,
      the confidentiality, integrity, and availability of services can be
      severely compromised, leading to data leaks, service outages, and
      potential financial losses for the organization relying on these
      microservices.</t>
    </section>

    <section title="Conventions used in this document">
      <t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
      "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
      document are to be interpreted as described in <xref target="RFC2119"/>
      .</t>
    </section>

    <section title="Architecture Goals">
      <section title="Dynamic Authentication">
        <t>In a distributed architecture where services are in a constant
        state of flux, static credentials and one - time verification
        processes are no longer adequate to fend off threats. Dynamic
        authentication is designed to overcome this shortcoming by
        continuously validating the identities and permissions of services in
        real - time. Through this continuous verification of service
        identities and permissions, it is ensured that only legitimate
        services with appropriate privileges are allowed to interact.</t>
      </section>

      <section title="Zero Trust">
        <t>Zero trust does not trust any microservice based on boundaries or a
        single attribute. Instead, every microservice is regarded as a
        potentially untrusted entity, and access is authorized on a per -
        request basis. Zero - trust communication ensures that access is
        restricted to the minimum necessary level, minimizing the potential
        impact of security vulnerabilities.</t>
      </section>
    </section>

    <section title="Technical Design">
      <t>In this draft, we defined a dynamic trust security architecture based
      on DMSC.</t>
    </section>

    <section title="Key Mechanisms">
      <section title="Dynamic Service Identity and Authentication">
        <t>Each microservice obtains a unique Service Verifiable Identity
        Document (SVID) from a trusted third - party upon startup. The SVID
        contains an encrypted and signed certificate and a globally unique
        SVID. During service registration, the Service Gateway (SG) strictly
        verifies the signature chain of the SVID to ensure that it is issued
        by a trusted third - party and is strongly bound to the Pod metadata
        to prevent identity forgery.</t>

        <t>To defend against replay attacks, before initiating a request, a
        service needs to apply for a dynamic token from the Service Prefix
        Authentication entity (SPA). This token is generated using the HMAC
        algorithm, incorporating a timestamp, a random number, and the SVID.
        When the SG processes a request, it not only verifies the signature
        validity of the token but also checks the timestamp deviation and the
        uniqueness of the random number, intercepting expired or duplicate
        requests.</t>
      </section>

      <section title="Dynamic Trust Access Control">
        <t>Access control policies are dynamically generated with the SVID as
        the core attribute, combined with the real - time scheduling data of
        the SCSC. Policy rules are pushed from the SCSC to the SG and the SR.
        The policy execution module embedded in the SG extracts the service
        prefix of the request during runtime and caches the results in high -
        concurrency scenarios to reduce latency. When an anomaly is detected,
        the SCSC issues a circuit - breaker policy, and the SG immediately
        intercepts the abnormal traffic. For data - plane communication
        between services, mTLS and the principle of least privilege are
        enforced.</t>
      </section>
    </section>

    <section title="Security Considerations">
      <t>TBD</t>
    </section>

    <section anchor="iana-considerations">
      <name>IANA Considerations</name>

      <t>No IANA action is required.</t>
    </section>
  </middle>

  <back>
    <references title="Informative References">
      <?rfc include="reference.I-D.li-dmsc-architecture"?>

      <reference anchor="RFC2119">
        <front>
          <title>Key words for use in RFCs to Indicate Requirement
          Levels</title>

          <author initials="S." surname="Bradner"/>

          <date month="March" year="1997"/>
        </front>
      </reference>
    </references>
  </back>
</rfc>
