SEA-06: Defense-In-Depth (DiD) Architecture
Mechanisms exist to implement security functions as a layered structure minimizing interactions between layers of the design and avoiding any dependence by lower layers on the functionality or correctness of higher layers.
Renumbered: Formerly NET-02 and SEA-03 in SCF 2025.4.
Code reused: In SCF 2025.4 and earlier, SEA-06 was Prevent Program Execution. That control is now CFG-14.
Control Question: Does the organization implement security functions as a layered structure minimizing interactions between layers of the design and avoiding any dependence by lower layers on the functionality or correctness of higher layers?
General (31)
US (15)
| Framework | Mapping Values |
|---|---|
| USA Federal CISA CPG 2022 | 1.E 2.X |
| USA Federal C2M2 2.1 | ARCHITECTURE-1b ARCHITECTURE-2c |
| USA Federal CMMC 2.0 Level 2 | SCL2.-3.13.2 |
| USA Federal CMMC 2.0 Level 3 | SC.L3-3.13.4E |
| USA Federal DoD Zero Trust Reference Architecture 2.0 | 3.0 |
| USA Federal 21 CFR Part 11 2025 | 11.10 |
| USA Federal FFIEC ITEH 2016 | II.C.3 |
| USA Federal IRS 1075 2021 | PL-8(CE-1) PL-8(CE-1).a PL-8(CE-1).b |
| USA Federal 33 CFR Part 101 Subpart F | 101.650(e)(3)(iv) |
| USA Federal FTC Act 1938 | 45(a)(1) |
| USA Federal HIPAA Security Rule NIST SP 800-66 R2 | § 164.306(b)(1) |
| USA Federal HIPAA Administrative Simplification 2013 | § 164.306(b)(1) |
| USA Federal NRC 10 CFR 73.54 2015 | 73.54(c)(2) |
| USA California CCPA 2025 | 7123(c)(5)(B) 7123(c)(8)(A) 7123(c)(10) |
| USA New York DFS 23 NYCRR500 2023 Amd 2 | 500.2(b)(2) |
EMEA (8)
| Framework | Mapping Values |
|---|---|
| EMEA Germany C5 2026 | IAM-07.02B COS-01.02B COS-02.01B |
| EMEA Spain CCN-STIC 825 | op.mon.1 mp.com.1 |
| EMEA EU DORA 2023 | Article 9.3(a) Article 9.3(b) Article 9.3(c) Article 9.3(d) |
| EMEA EU DORA RTS 2024 | Article 13.1(f) |
| EMEA EU EBA GL/2019/04 | 3.7.1.79 |
| EMEA Israel CDMO 2.0 | 2.E |
| EMEA Saudi Arabia CSCC-1 2019 | 2-4-1-5 |
| EMEA Saudi Arabia ECC-1 2018 | 2-5-3-8 2-15-3-2 |
APAC (4)
| Framework | Mapping Values |
|---|---|
| APAC Australia ISM June 2026 | ISM-1739 |
| APAC India RBI Digital Payments 2021 | 19.0 |
| APAC Malaysia RMiT 2025 | 11.3(d) 12.3(b) A7-D2(d)(ii) |
| APAC Singapore CCOP CII 2026 | 3.7.1(a) A.2.1 |
Americas (4)
| Framework | Mapping Values |
|---|---|
| Americas Bermuda BMACCC 2020 | 6.18 |
| Americas Canada ITSP-10-171 2025 | 03.13.01.B |
| Americas Canada OSFI B-13 2022 | 3.2 3.2.4 |
| Americas Canada OSFI Self-Assessment Guidance | 3.2.4 |
Capability Maturity Model
Level 0 — Not Performed
Practices are non-existent, based on the inability to demonstrate an implemented and operational capability. A reasonable person would conclude the control is not being performed.
Level 1 — Performed Informally
Network Security (NET) domain capabilities are ad hoc and inconsistent. Capability criteria associated with this control may include: ▪ Policies, standards & procedures associated with NET domain capabilities provide limited coverage due to the depth and breadth of the existing documentation. ▪ Network security-related activities are decentralized (e.g., a localized/regionalized function) and uses non-standardized methods to implement secure, resilient and compliant practices. ▪ Administrative processes are used to configure boundary devices (e.g., firewalls and routers) to deny network traffic by default and allow network traffic by exception (e.g., deny all and permit by exception).
Level 2 — Planned & Tracked
Secure Engineering & Architecture (SEA) capabilities are requirements-driven, but are not standardized across the entity (e.g., local/regional level consistency). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with SEA domain capabilities are formally documented and centrally-managed by the entity. ▪ Standardized Operating Procedures (SOP) associated with SEA domain capabilities are documented and maintained by process owners. ▪ IT and/or cybersecurity personnel work with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with SEA domain capabilities to address applicable statutory, regulatory and/or contractual requirements for Technology Assets, Applications, Services and/or Data (TAASD). ▪ Secure engineering and architecture-related controls are primarily administrative and preventative in nature (e.g., policies, standards and procedures & guidelines). ▪ Secure engineering and architecture management may be a defined function (e.g., team or department) or assigned as an additional duty to existing IT and/or cybersecurity personnel. ▪ IT and/or cybersecurity personnel define entity-specific secure engineering practices to protect the Confidentiality, Integrity, Availability and Safety (CIAS) of the entity's TAASD. ▪ IT and/or cybersecurity personnel align secure engineering practices with the entity's broader IT architecture practices. ▪ IT and/or cybersecurity personnel use secure engineering practices to influence Secure Baseline Configurations (SBC). ▪ IT and/or cybersecurity personnel manage separate development, testing and operational environments to reduce the risks of unauthorized access or changes to the operational environment and to ensure no impact to production TAASD.
Level 3 — Well Defined
Secure Engineering & Architecture (SEA) capabilities are standardized across the entity for applicability to People, Processes, Technologies, Data and/or Facilities (PPTDF) to ensure consistency for Technology Assets, Applications, Services and/or Data (TAASD). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with SEA domain capabilities are formally documented and centrally-managed by the entity's Governance, Risk & Compliance (GRC) team, or similar function. ▪ Standardized Operating Procedures (SOP) associated with SEA domain capabilities are well-documented and kept current by process owners. ▪ A cybersecurity engineering / architecture team, or similar function, is appropriately staffed and supported to implement and maintain RSK domain capabilities. ▪ Technology is leveraged to enhance the efficiency and accuracy of secure engineering management operations (e.g., project management solution). ▪ The entity's Governance, Risk & Compliance (GRC) team, or similar function, works with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with SEA domain capabilities to address Minimum Compliance Requirements (MCR) (e.g., applicable statutory, regulatory and/or contractual requirements) and Discretionary Security Requirements (DSR) (e.g., entity-required controls). ▪ Secure Baseline Configurations (SBC) enforce the secure engineering principles on all applicable Technology Assets, Applications and/or Services (TAAS). ▪ An implemented and operational capability exists to implement security functions as a layered structure minimizing interactions between layers of the design and avoiding any dependence by lower layers on the functionality or correctness of higher layers.
Level 4 — Quantitatively Controlled
Network Security (NET) capabilities, in addition to being standardized across the entity and centrally managed to ensure consistency across Technology Assets, Applications, Services and/or Data (TAASD), efforts are metrics driven to provide sufficient insight for decision makers to predict optimal performance, ensure continued operations and/or identify areas for improvement. Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Applicable SCR-CMM Level 3 (Well Defined) capabilities are implemented and operational. ▪ Metrics reporting includes quantitative analysis of Key Performance Indicators (KPIs). ▪ Metrics reporting includes quantitative analysis of Key Risk Indicators (KRIs). ▪ Scope of metrics, KPIs and KRIs covers organization-wide cybersecurity and data protection controls, including functions performed by third-parties. ▪ Organizational leadership maintains a formal process to objectively review and respond to metrics, KPIs and KRIs (e.g., monthly or quarterly review). ▪ Based on metrics analysis, process improvement recommendations are submitted for review and are handled in accordance with change control processes. ▪ Business and technical stakeholders are involved in reviewing and approving proposed changes to evolve capabilities.
Level 5 — Continuously Improving
Utilize SCR-CMM Level 3 or Level 4 (if available) criteria definitions: ▪ There are no defined Level 5 criteria, since it is reasonable to assume a continuously-improving process is not necessary to operationalize this control. ▪ Level 5 capabilities should be considered “world-class” where the control builds on Level 4 capabilities, but are continuously improving through Artificial Intelligence (AI) and/or Machine Learning (ML) technologies. ▪ While it may be possible to develop responsive capabilities for this control through the use of AI and/or ML technologies, the criteria would be organization-specific to define.
Assessment Objectives
- SEA-06_A01 security functions are implemented as a layered structure, minimizing interactions between layers of the design and avoiding any dependence by lower layers on the functionality or correctness of higher layers.
- SEA-06_A02 the cybersecurity / data privacy architecture for the system is designed using a defense-in-depth approach that allocates controls to locations and architectural layers.
- SEA-06_A03 the cybersecurity / data privacy architecture for the system is designed using a defense-in-depth approach that ensures the allocated controls operate in a coordinated and mutually reinforcing manner.
- SEA-06_A04 controls to be allocated are defined.
- SEA-06_A05 locations and architectural layers are defined.
Evidence Requirements
- E-SEA-02 Security Architecture
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Documented evidence of security architecture-related documentation.
Secure Engineering & Architecture
Technology Recommendations
Micro/Small
- Defined "secure engineering principles" (e.g., alignment with NIST 800-160)
- Defense-in-depth (DiD) architecture
Small
- Defined "secure engineering principles" (e.g., alignment with NIST 800-160)
- Defense-in-depth (DiD) architecture
Medium
- Defined "secure engineering principles" (e.g., alignment with NIST 800-160)
- Defense-in-depth (DiD) architecture
- Enterprise architecture committee
Large
- Defined "secure engineering principles" (e.g., alignment with NIST 800-160)
- Defense-in-depth (DiD) architecture
- Enterprise architecture committee
Enterprise
- Defined "secure engineering principles" (e.g., alignment with NIST 800-160)
- Defense-in-depth (DiD) architecture
- Enterprise architecture committee