Discussion period begins: NS-009: Permit Log Storage Systems to be operated in Third Party-Controlled Environments

[Corey Bonnell]

This ballot introduces a new section (Section 5) to the Network and Certificate System Security Requirements (NCSSRs) to permit Log Storage Systems to be operated in Third Party-Controlled Environments (e.g., cloud service providers), subject to risk assessment, shared responsibility, and data integrity/retention requirements. Specifically:

 

- Adds a definition for **Log Storage System**: the system(s) used for long-term, authoritative retention of audit logs, including any backup or recovery system intended to restore the authoritative copy.

- Adds a definition for **Third Party-Controlled Environment**: a Physically Secure Environment where physical and operational control is managed by a third-party service provider rather than the CA.

- Adds a definition for **Shared Responsibility Model**: a security framework describing the division of security responsibilities between the third-party service provider and the CA.

- Modifies the **CA Infrastructure** definition to include Log Storage Systems.

- Modifies **Section 1.2.1** to require that Certificate Systems, Root CA Systems, and Security Support Systems remain in a CA-Controlled Environment, while permitting Log Storage Systems to operate in either a CA-Controlled Environment or a Third Party-Controlled Environment meeting the requirements of new Section 5.

- Adds **Section 5 (Requirements for Third Party-Controlled Environments)**, consisting of:

  - Section 5.1 (Risk Assessment): Requires the CA to perform and document a risk assessment of the third-party service provider.

  - Section 5.2 (Shared Responsibility): Requires the CA to configure systems per the provider's documentation and shared responsibility model, and to document how its configuration satisfies its allocated responsibilities.

  - Section 5.3 (Data Integrity and Retention): Requires that logs be configured to prevent modification or deletion for the required retention period using provider-native immutability features (e.g., WORM, Object Locks), and that the CA verify this configuration at least annually.

 

Note: This ballot does not address a gap identified during discussion regarding whether the physical security requirements of a Physically Secure Environment must be directly fulfilled by facilities that the CA owns and operates, or whether those obligations can be fulfilled by a third party (e.g., a data center). This gap will be resolved in a future ballot.

 

This ballot is proposed by Corey Bonnell (DigiCert) and endorsed by Trevoli Ponds-White (Amazon Trust Services) and Ben Wilson (Mozilla).

 

Motion

 

**Motion Begins**

 

This ballot modifies the Network and Certificate System Security Requirements (NCSSRs), based on Version 2.0.5.

 

MODIFY the NCSSRs as specified in the following Redline:

https://github.com/cabforum/netsec/compare/8130aee66836fe0a9d36cf9322af3cd552220d97...18c9defcb66ab3f4125f43eac7a6ff3b3a91cef4

 

**Motion Ends**

 

---

 

**Discussion** (at least 7 days)

 

- Start time: 2026-05-11 12:30 UTC

- End time: on or after 2026-05-26 12:30 UTC

 

**Vote for approval** (7 days)

 

- Start time: TBD

- End time: TBD (Start time + 7 days)

 

 

[Martijn Katerbarg]

Thanks for this ballot Corey.

Reviewing this, there’s one item which worries me, and that’s the scope of "**CA-Controlled Environment:** A Physically Secure Environment where physical and operational control is managed by the Certificate Authority (the organization) and not operated by a third-party service provider.”

Mainly, how does this affect Certificate Systems which are housed in a datacenter operated by a third party, but where the CA has a secure cage, allowing only their own employees access to racks housing certificate systems. Do we consider the innerst most accesst the CA-Controlled Physically Secure Environment, without potentially leading to audit failures and incidents, due to a third party operating the remainer of the perimiters? 

Regards,

Martijn

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[Dustin Hollenback]

Hi Corey,

Thank you for the ballot and the work that went into it. I support the intent and direction. However, after more discussion on the NetSec WG workshop call today, I think we should address the colocation gap in this ballot rather than deferring it to a future one. The more this comes up, the more I think it’s serious enough to just solve now. There was a suggestion to remove CA-Controlled Environment as a definition in this ballot, but after more thought, I think that sends us in the wrong direction of being less clear than more clear.

Additionally, there is a potential definition interpretation overlap between Security Support System and Log Storage System that should be cleaned up to avoid interpretation issues.

Here is my reasoning:

1. THE COLOCATION GAP

The ballot's note acknowledges a gap: "whether the physical security requirements of a Physically Secure Environment must be directly fulfilled by facilities that the CA owns and operates, or whether those obligations can be fulfilled by a third party (e.g., a data center).” This was what we first agreed to, because the intent was to avoid complicating this ballot and instead defer that interpretation gap for the future.

On the additional NetSec WG working session meeting today, we discussed removing the "CA-Controlled Environment" definition and cleaning up the interpretation gaps for a later time. After that discussion, I believe we should solve the gap in this ballot for the following reasons:

a. The current definitions create a binary model: CA-Controlled Environment vs. Third Party-Controlled Environment. In practice, there are three distinct operational scenarios:

• Fully CA-Controlled: The CA owns and operates the entire facility, including building, HVAC, power, perimeter security, and all systems within it. (e.g., a CA-owned data center)
• Colocation: The CA operates its own systems within a facility managed by a third-party service provider. The CA controls its designated space (rack, cage, suite) and the hardware within it, but the third party manages facility-level controls like building perimeter security, HVAC, power, and fire suppression. (e.g., a leased cage in a commercial data center)
• Fully Third Party-Controlled: The CA has no physical access to or control over the underlying hardware. All physical and operational controls are managed by the third-party service provider. (e.g., AWS, Azure, GCP)

b. Colocation does not cleanly fit either existing definition. Calling it "CA-Controlled" requires an interpretation that a service contract equates to CA control of physical infrastructure. That is a squishy interpretation that different auditors will judge differently. Calling it "Third Party-Controlled" is equally wrong because the CA does have direct physical control over its own hardware.

c. Most CAs use colocation. If we ship this ballot with the gap, we are knowingly leaving the most common deployment model in an ambiguous state. Every CA and every auditor will have to independently decide how to classify colocation until the future ballot arrives. That will produce inconsistent compliance outcomes across the ecosystem.

d. The fix is well-scoped. It requires:

• Tightening the CA-Controlled Environment definition
• Adding a CA-Colocated Environment definition
• Tightening the Third Party-Controlled Environment definition
• Adding CA-Colocated Environment as a permitted placement in 1.2.1
• Adding a new Section 6 with colocation-specific requirements

From my understanding, none of these changes conflict with or complicate the existing ballot content. They extend it.

2. THE LOG STORAGE / SECURITY SUPPORT DEFINITION OVERLAP

The Security Support System definition includes "audit logging" and "audit log reduction and analysis" as example functions. The Log Storage System definition covers "long-term, authoritative retention of audit logs." These overlap enough that someone classifying a system that retains audit logs long-term may not be able to clearly distinguish which category it belongs to. Since the two categories have different placement rules in Section 1.2.1, this ambiguity could lead to inconsistent classification across CAs and auditors.

The fix is narrow: clarify in the Security Support System definition that "audit logging" refers to the generation and collection of audit logs, and that long-term retention is governed by the Log Storage System definition. This draws a clean functional line between the two categories without broad exclusions or loopholes.

Below is a complete redline incorporating both sets of changes.

================================================================================

PROPOSED REDLINE CHANGES TO NETWORK AND CERTIFICATE SYSTEM SECURITY REQUIREMENTS

================================================================================

Conventions:

  [-  deleted text  -]

  [+  added text  +]

  [NEW] = entirely new content

================================================================================

SECTION: Definitions

================================================================================

---------- DEFINITION: CA-Controlled Environment (MODIFIED) ----------

[-

CA-Controlled Environment: A Physically Secure Environment where physical and operational control is managed by the Certificate Authority (the organization) and not operated by a third-party service provider.

-]

[+

CA-Controlled Environment: A Physically Secure Environment where all physical and operational controls are exclusively managed by the Certificate Authority (the organization), including facility-level controls such as building perimeter security, physical access systems, power, environmental controls (e.g., HVAC), and fire suppression. No portion of the Physically Secure Environment's physical or environmental controls is operated by a third-party service provider.

+]

---------- DEFINITION: CA-Colocated Environment (NEW) ----------

[NEW]

[+

CA-Colocated Environment: A Physically Secure Environment in which:

1. the CA operates its own Systems within a facility managed by a third-party service provider;

2. the CA maintains direct physical control over its designated space (e.g., dedicated rack, cage, or suite) and the Systems within that space; and

3. the third-party service provider manages facility-level controls such as building perimeter security, physical access systems, power, environmental controls (e.g., HVAC), and fire suppression.

+]

---------- DEFINITION: Security Support System (MODIFIED) ----------

[-

Security Support System: The System(s) supporting the security of CA Infrastructure, performing functions such as:

   1. authentication;

   2. audit logging;

   3. audit log reduction and analysis;

   4. vulnerability scanning;

   5. physical intrusion detection;

   6. host-based intrusion detection; and

   7. network-based intrusion detection.

-]

[+

Security Support System: The System(s) supporting the security of CA Infrastructure, performing functions such as:

   1. authentication;

   2. generation and collection of audit logs;

   3. audit log reduction and analysis;

   4. vulnerability scanning;

   5. physical intrusion detection;

   6. host-based intrusion detection; and

   7. network-based intrusion detection.

The long-term, authoritative retention of audit logs is governed by the Log Storage System definition.

+]

---------- DEFINITION: Third Party-Controlled Environment (MODIFIED) ----------

[-

Third Party-Controlled Environment: A Physically Secure Environment where physical and operational control is not managed by the Certificate Authority (the organization) and is instead operated by a third-party service provider.

-]

[+

Third Party-Controlled Environment: A Physically Secure Environment where all physical and operational controls are managed by a third-party service provider. The CA does not maintain direct physical access to, or physical control over, the underlying hardware or the facility in which it operates.

+]

================================================================================

SECTION 1.2.1: CA Infrastructure Security (MODIFIED)

================================================================================

[-

##### 1.2.1

Certificate Systems, Root CA Systems (Air-gapped or otherwise), and Security Support Systems MUST be in a CA-Controlled Environment.

Log Storage Systems MUST either:

1. be in a CA-Controlled Environment, or

2. be in a Third Party-Controlled Environment that fulfills the requirements of Section 5.

Root CA Systems MUST be on physically separate networks from all other CA Infrastructure.

-]

[+

##### 1.2.1

Certificate Systems, Root CA Systems (Air-gapped or otherwise), and Security Support Systems MUST be in:

1. a CA-Controlled Environment; or

2. a CA-Colocated Environment that fulfills the requirements of Section 6.

Log Storage Systems MUST be in:

1. a CA-Controlled Environment;

2. a CA-Colocated Environment that fulfills the requirements of Section 6; or

3. a Third Party-Controlled Environment that fulfills the requirements of Section 5.

Root CA Systems MUST be on physically separate networks from all other CA Infrastructure.

+]

================================================================================

SECTION 6: Requirements for CA-Colocated Environments (NEW)

================================================================================

[NEW]

[+

# 6. Requirements for CA-Colocated Environments

The requirements of this section MUST be fulfilled for all Systems which are operated in a CA-Colocated Environment.

## 6.1 Service Agreement

The CA MUST maintain a documented service agreement with the operator of the CA-Colocated Environment that addresses:

1. the facility-level physical security controls provided by the third-party service provider, including, at minimum, controls addressing the topics outlined in Section 4.5.1 of RFC 3647;

2. the delineation of responsibilities between the CA and the third-party service provider for each aspect of physical and environmental security;

3. the CA's right to audit or obtain independent audit reports covering the third-party service provider's facility-level controls;

4. incident notification requirements, including timelines for the third-party service provider to notify the CA of physical security incidents that may affect the CA's designated space; and

5. the conditions and procedures under which the third-party service provider may access the CA's designated space.

## 6.2 Risk Assessment

The CA MUST perform a risk assessment of the third-party service provider operating the CA-Colocated Environment. The risk assessment MUST:

1. evaluate the adequacy of the third-party service provider's facility-level physical and environmental security controls;

2. be performed prior to initial use and reviewed at least annually thereafter; and

3. document the evidence relied upon in performing the risk assessment, which MAY include independently audited or certified reports (e.g., SOC 2 Type II, ISO/IEC 27001).

## 6.3 Physical Access Controls

The CA MUST ensure that:

1. the CA's designated space within the CA-Colocated Environment is physically separated from spaces controlled by other tenants through mechanisms such as locked cages, locked cabinets, or dedicated suites;

2. physical access to the CA's designated space is restricted to personnel assigned to applicable Trusted Roles;

3. the CA maintains independent control over the access credentials (e.g., keys, locks, access cards, biometric enrollment) for its designated space; and

4. the third-party service provider's access to the CA's designated space, if any, is:

   a. governed by documented procedures that are consistent with the CA's physical access policies;

   b. escorted by, or conducted with the prior authorization and knowledge of, personnel assigned to applicable Trusted Roles; and

   c. logged and reviewed by the CA.

Where Root CA Systems are housed in a CA-Colocated Environment, the CA MUST additionally ensure that the third-party service provider cannot independently access the CA's designated space without the presence of personnel assigned to applicable Trusted Roles.

## 6.4 Monitoring and Verification

The CA MUST:

1. verify, at least annually, that the third-party service provider's facility-level controls continue to satisfy the CA's risk assessment; and

2. review physical access logs for the CA's designated space at least quarterly.

+]

================================================================================

SECTION: Document History (MODIFIED -- add new row)

================================================================================

[+

| 2.0.6 | NS-XXX | Address the colocation gap: introduce CA-Colocated Environment definition and requirements; tighten CA-Controlled Environment and Third Party-Controlled Environment definitions to create three distinct environment classifications; clarify Security Support System definition to draw a clean boundary with Log Storage System | DD-MMM-YYYY | DD-MMM-YYYY |

+]

================================================================================

SUMMARY OF CHANGES

================================================================================

Change                                | Type    | Rationale

--------------------------------------|---------|---------------------------------------------

CA-Controlled Environment definition  | Tighten | Make explicit that the CA controls all layers including building, HVAC, power, perimeter security.

CA-Colocated Environment definition   | New     | Define the colocation scenario as its own distinct category where the CA controls its space/hardware but not the facility.

Security Support System definition    | Clarify | Change "audit logging" to "generation and collection of audit logs" and add a sentence clarifying that long-term retention is governed by the Log Storage System definition. This draws a precise functional boundary without broad exclusions.

Third Party-Controlled Environment    | Tighten | Clarify that this applies only when the CA has no physical access to or control over hardware.

Section 1.2.1                         | Expand  | Add CA-Colocated Environment as a permitted option for all system types. Preserve the original restriction that only Log Storage Systems may reside in Third Party-Controlled Environments.

Section 6 (new)                       | New     | Establish colocation-specific obligations: service agreements, risk assessments, physical access controls, and ongoing verification.

================================================================================

SYSTEM TYPE PLACEMENT MATRIX

================================================================================

System Type              | CA-Controlled | CA-Colocated    | Third Party-Controlled

-------------------------|---------------|-----------------|------------------------

Certificate Systems      | Yes           | Yes (w/ Sec. 6) | No

Security Support Systems | Yes           | Yes (w/ Sec. 6) | No

Root CA Systems          | Yes           | Yes (w/ Sec. 6) | No

Log Storage Systems      | Yes           | Yes (w/ Sec. 6) | Yes (w/ Sec. 5)

[Corey Bonnell]

Hi Dustin,

Thank you for the additional feedback and the concrete text suggestions. I incorporated all of them, but also switched the ordering of sections 5 and 6 so that the references in 1.2.1 read sequentially.

 

Look forward to additional discussion on today’s call.

 

Thanks,

Corey

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