CDP Audit Trail Documentation — Verification Chain of Custody

Table of Contents

1. [Introduction](#introduction)
2. [Chain of Custody](#chain-of-custody)

• 2.1. Overview
• 2.2. Data Flow Diagram
• 2.3. Data Field Mappings

1. [Data Integrity](#data-integrity)

• 3.1. Data Capture
• 3.2. Data Processing
• 3.3. Data Reporting

1. [Timestamp Verification](#timestamp-verification)

• 4.1. Timestamp Standards
• 4.2. Time Synchronization Protocol

1. [Tamper Detection](#tamper-detection)

• 5.1. Tamper Detection Mechanisms
• 5.2. Data Validation Procedures

1. [Audit Log Format](#audit-log-format)

• 6.1. Log Structure
• 6.2. Log Retention Policy

1. [Conformity Assessment Procedures](#conformity-assessment-procedures)
2. [Conclusion](#conclusion)

1. Introduction

This document outlines the comprehensive audit trail requirements established by the CDP (formerly Carbon Disclosure Project) for organizations utilizing sensor-based Measurement, Reporting, and Verification (MRV) platforms in carbon markets. It serves as a guideline for ensuring compliance with the CDP's global disclosure system for environmental reporting, which is aligned with the TCFD (Task Force on Climate-related Financial Disclosures) and ISSB (International Sustainability Standards Board) frameworks.

The purpose of this document is to provide a clear and structured approach to documenting the end-to-end audit trail from sensor measurement through verification to credit issuance, ensuring data integrity, timestamp verification, tamper detection, and adherence to audit log standards.

2. Chain of Custody

2.1. Overview

The chain of custody (CoC) is a critical component of the audit trail, ensuring that all data collected from IoT sensors is traceable, verifiable, and securely managed throughout its lifecycle. The CoC shall encompass the following stages:

1. Data Acquisition: Collection of environmental data via IoT sensors.
2. Data Transmission: Secure transfer of data to processing systems.
3. Data Processing: Application of certified algorithms to derive meaningful insights.
4. Data Reporting: Generation of verification-ready reports.

2.2. Data Flow Diagram

The Data Flow Diagram (DFD) illustrates the flow of data through the MRV platform, detailing the interactions between sensors, data storage, processing algorithms, and reporting modules.

` [IoT Sensors] → [Data Transmission (API)] → [Data Storage] → [Data Processing] → [Verification Reports] `

2.3. Data Field Mappings

The following data fields shall be captured and mapped throughout the chain of custody:

| Field Name | Data Type | Description | Source | |---------------------|--------------------|------------------------------------------------------|----------------------| | Sensor_ID | String | Unique identifier for each sensor | IoT Sensor | | Timestamp | ISO 8601 DateTime | Date and time of data capture | IoT Sensor | | Environmental_Data | Float | Measured environmental parameter (e.g., CO2 levels) | IoT Sensor | | Location | String | Geographical location of the sensor | IoT Sensor | | Algorithm_Version | String | Version of the algorithm used for data processing | Processing Module | | Report_ID | String | Unique identifier for generated reports | Reporting Module | | Verification_Status | Enum | Status of verification (e.g., Pending, Verified) | Verification Module | | Issued_Credits | Integer | Number of credits issued based on verified data | Credit Issuance |

3. Data Integrity

3.1. Data Capture

Data captured by the IoT sensors shall be transmitted securely to the data storage system using HTTPS protocol. Each data transmission shall include a checksum to ensure integrity during transit.

3.2. Data Processing

Data processing shall be performed using certified algorithms that comply with recognized standards for environmental data analysis. The algorithms shall be documented, and any changes to the algorithms shall be version-controlled and auditable.

3.3. Data Reporting

Generated reports must include:

• All captured data fields.
• A summary of the verification process.
• The final verification status.
• A unique report identifier.

The reports shall be generated in a standardized format (e.g., JSON or XML) to facilitate integration with the CDP reporting framework.

4. Timestamp Verification

4.1. Timestamp Standards

Timestamps shall adhere to the ISO 8601 standard (YYYY-MM-DDTHH:MM:SSZ) to ensure consistency and interoperability across systems.

4.2. Time Synchronization Protocol

All IoT sensors and processing systems shall synchronize their clocks with an authoritative time source (e.g., NTP server) to ensure accurate timestamping of data. The synchronization interval shall not exceed 1 hour.

5. Tamper Detection

5.1. Tamper Detection Mechanisms

Tamper detection mechanisms shall be implemented to monitor and alert on unauthorized access or alterations to the data. These mechanisms may include:

• Hashing algorithms (e.g., SHA-256) applied to data sets.
• Access control logs to track user interactions with data.
• Anomaly detection systems to identify irregular patterns in data access.

5.2. Data Validation Procedures

Data validation procedures shall be established to ensure the accuracy and completeness of collected data. This includes:

• Cross-verification of sensor readings against expected ranges.
• Routine audits of data integrity and consistency.

6. Audit Log Format

6.1. Log Structure

Audit logs shall be generated in a structured format (JSON) and must include the following fields:

| Field Name | Data Type | Description | |------------------|-----------|-----------------------------------------------| | Log_ID | String | Unique identifier for each log entry | | Timestamp | ISO 8601 | Date and time of the log entry | | User_ID | String | Identifier of the user who performed the action | | Action_Type | String | Type of action performed (e.g., Create, Update, Delete) | | Affected_Resource| String | Identifier of the resource affected | | Status | String | Status of the action (e.g., Success, Failure)| | Comments | String | Additional comments or details about the action|

6.2. Log Retention Policy

Audit logs shall be retained for a minimum of five (5) years to comply with regulatory requirements and to facilitate future audits. Logs shall be stored in a secure, tamper-evident environment.

7. Conformity Assessment Procedures

To ensure compliance with CDP standards, the following conformity assessment procedures shall be implemented:

1. Pre-Implementation Review: An initial review of the MRV platform's design and architecture against CDP requirements shall be conducted prior to deployment.

1. Data Integrity Testing: Regular testing of data capture, processing, and reporting mechanisms shall be performed to ensure ongoing compliance with data integrity requirements.

1. Audit Trail Verification: Periodic audits of the audit trail shall be conducted to verify the completeness and accuracy of the chain of custody.

1. Third-Party Certification: Where applicable, third-party certification of the MRV platform and its components shall be obtained to ensure adherence to recognized standards.

1. Continuous Monitoring: Ongoing monitoring of the system shall be implemented to detect and address any deviations from compliance requirements promptly.

8. Conclusion

This document provides a comprehensive framework for establishing a robust audit trail for sensor-based MRV platforms used in carbon markets, in alignment with CDP's global disclosure system. By adhering to the outlined requirements for chain of custody, data integrity, timestamp verification, tamper detection, and audit log formats, organizations can ensure transparency, accountability, and reliability in their environmental reporting practices. Compliance with these standards will facilitate the accurate assessment of climate action initiatives and support the overarching goals of the CDP.