ISO 27001 Encryption and Key Management Procedure Template

Introduction

Encryption is a critical security measure for protecting information stored on devices, systems, databases, cloud platforms, backup media, and other repositories. It is also widely used to protect information transmitted between users, applications, offices, suppliers, and external services.  However, deploying encryption technology is only part of the solution. If cryptographic keys are generated poorly, stored with the encrypted information, shared without control, used beyond their approved purpose, or retained after compromise, the protection provided by encryption can be seriously weakened. An ISO 27001 Encryption and Key Management Procedure translates the organization’s high-level cryptographic policy into operational instructions. It defines when cryptography is required, identifies approved technologies and responsibilities, and establishes controls for the full lifecycle of keys, certificates, secrets, and other cryptographic material.

ISO 27001 Requirements Relevant to Cryptography

The primary ISO/IEC 27001:2022 Annex A control for encryption and key management is:

• Control 8.24 – Use of cryptography: Supports the definition and implementation of rules for the effective use of cryptography, including cryptographic key management.
  
  

Other controls that may support or depend on cryptography include:

• Control 5.14 – Information transfer: Supports rules, procedures, and agreements for protecting information transferred within the organization and with external parties.
  
  

• Control 5.17 – Authentication information: Supports appropriate allocation and management of passwords, tokens, keys, certificates, and other authentication information.
  
  

• Control 5.19 to 5.23 – Supplier and cloud-service controls: Support the management of security requirements, changes, supply-chain risks, and cloud-service responsibilities, including cryptographic responsibilities where relevant.
  
  

• Control 8.12 – Data leakage prevention: Supports controls that reduce unauthorized disclosure or extraction of sensitive information.
  
  

• Control 8.13 – Information backup: Supports protection, maintenance, and testing of backups according to agreed requirements.
  
  

• Control 8.15 – Logging: Supports the recording, protection, storage, and analysis of relevant events.
  
  

• Control 8.16 – Monitoring activities: Supports monitoring for anomalous behavior and potential information security incidents.
  
  

• Controls 8.20 and 8.21 – Network security and security of network services: Support protection of networks and the establishment of security mechanisms and service requirements.
  
  

• Controls 8.25 and 8.26 – Secure development lifecycle and application security requirements: Support integration of cryptographic requirements into development and application design where appropriate.

Cryptography should be selected through risk assessment, legal and contractual analysis, information classification, and technical evaluation. ISO 27001 does not prescribe one universal algorithm, key length, certificate type, or cryptographic product for every organization.

Why a Dedicated Encryption and Key Management Procedure Is Needed

• Consistent implementation: Teams follow common rules rather than selecting incompatible or insecure methods independently.
  
  

• Controlled key lifecycle: Keys are generated, stored, distributed, used, rotated, revoked, recovered, archived, and destroyed through approved processes.
  
  

• Clear accountability: Information owners, security specialists, administrators, developers, custodians, and suppliers understand their responsibilities.
  
  

• Reduced security risk: Weak algorithms, exposed keys, uncontrolled certificates, embedded secrets, and unsupported protocols can be identified and addressed.
  
  

• Operational resilience: Backup, recovery, escrow, succession, and emergency arrangements reduce the risk of permanent data loss.
  
  

• Incident readiness: The organization has defined actions for suspected key compromise, certificate misuse, failed encryption, or cryptographic weakness.
  
  

• Audit evidence: Approvals, inventories, logs, rotations, access records, tests, exceptions, incidents, and reviews demonstrate controlled operation.
  
  

• Legal and contractual alignment: The procedure helps implement applicable requirements relating to confidentiality, electronic signatures, regulated information, key custody, and cross-border transfer.

A high-level cryptographic policy states management expectations. The procedure explains how authorized personnel implement those expectations in practice.

1. Governance, Scope, and Cryptographic Requirements

This component defines the organizational rules that determine where cryptography is required and how decisions are governed.

• Purpose: State that the procedure protects the confidentiality, integrity, authenticity, and, where applicable, non-repudiation of information through controlled cryptographic measures.
  
  

• Scope: Identify the legal entities, personnel, systems, applications, networks, cloud services, suppliers, development environments, devices, information classes, and locations covered.
  
  

• Information classification: Link encryption decisions to approved classification and handling requirements.
  
  

• Risk assessment: Require cryptographic controls where the assessed risk and treatment decisions justify them.
  
  

• Legal and contractual review: Identify applicable restrictions, electronic-signature rules, export or import controls, regulated algorithms, data-location requirements, and customer commitments.
  
  

• Approved cryptographic standard: Maintain a separate technical standard listing approved algorithms, modes, protocols, key sizes, certificate profiles, libraries, modules, and deprecation dates.
  
  

• Prohibited methods: Identify obsolete, weak, internally invented, or otherwise unapproved cryptographic methods and protocols.

• Approved products and services: Define evaluation and approval requirements for cryptographic libraries, cloud KMS platforms, HSMs, certificate services, encrypted communication tools, and endpoint encryption.

• Separation of duties: Separate key approval, creation, custody, use, recovery, and destruction where risk requires it.

• Exception process: Require documented business justification, risk assessment, compensating controls, approval, owner, and expiry date.

• Supplier requirements: Define cryptographic responsibilities, access, notification, evidence, key ownership, data return, deletion, and exit requirements in agreements.

• Related documents: Reference the information security, access-control, classification, secure-development, backup, incident-response, supplier, and records-management documents.

The approved cryptographic standard should be reviewed more frequently than the general procedure when technology, threats, regulatory guidance, or industry recommendations change.

2. Cryptographic Implementation and Technical Control

This component explains how approved cryptography is applied in different technical and operational contexts.

• Information at rest: Define requirements for databases, file systems, object storage, cloud services, virtual machines, removable media, endpoints, mobile devices, exports, and archives.
  
  

• Information in transit: Define requirements for web traffic, application interfaces, administrative connections, email, file transfer, messaging, remote access, and internal or external network communication.
  
  

• Backups: Define encryption, key separation, recovery, portability, supplier, and restoration requirements for backup copies and media.
  
  

• End-user devices: Define full-disk, file, container, mobile-device, removable-media, secure-boot, and recovery requirements according to risk.
  
  

• Cloud services: Define customer-managed or provider-managed key decisions, tenant controls, regions, access, logging, rotation, deletion, recovery, and exit requirements.
  
  

• Applications: Define how developers select approved libraries, protect secrets, validate certificates, handle errors, and avoid custom cryptographic implementations.
  
  

• Databases: Define column, field, table, file, volume, or service-level encryption based on information sensitivity and threat scenarios.
  
  

• Network services: Require approved protocols, certificate validation, secure configurations, and the disabling of obsolete protocol versions and cipher suites.
  
  

• Email and file exchange: Define approved methods for encrypting sensitive messages, attachments, portals, shared links, and transferred files.
  
  

• Portable and removable media: Restrict use, require approval, enforce encryption, record custody, and define secure disposal where relevant.
  
  

• Key separation: Prevent encryption keys from being stored with protected data without suitable safeguards and access separation.
  
  

• Test and development data: Apply controls to sensitive test data and prohibit uncontrolled use of production secrets in development environments.
  
  

• Configuration management: Maintain secure baselines, change control, peer review, testing, rollback, and documentation for cryptographic configurations.
  
  

• Validation: Confirm that encryption is enabled, correctly configured, effective, recoverable, and applied to the intended information and pathways.

The procedure should avoid treating encryption as a substitute for access control, secure configuration, monitoring, backup, or other required safeguards. Cryptography is one part of a layered security design.

3. Key, Certificate, and Secret Lifecycle Management

This component governs cryptographic material from creation through final destruction.

• Inventory: Maintain an inventory of keys, certificates, secrets, tokens, owners, custodians, systems, purposes, algorithms, creation dates, expiry dates, and status.
  
  

• Generation: Generate keys using approved methods, trusted cryptographic modules, suitable entropy, and authorized procedures.
  
  

• Purpose assignment: Restrict each key to its approved purpose, system, environment, and operation where technically feasible.
  
  

• Ownership and custody: Assign accountable owners and authorized custodians for keys and cryptographic services.
  
  

• Storage: Store keys in approved KMS platforms, HSMs, secure vaults, trusted hardware, or other protected mechanisms appropriate to risk.
  
  

• Access control: Apply least privilege, strong authentication, administrative separation, dual control, just-in-time access, and periodic review as appropriate.
  
  

• Distribution and exchange: Use approved secure channels, authenticated endpoints, key wrapping, trusted couriers, or controlled ceremonies depending on the key type and risk.
  
  

• Activation: Confirm authorization, configuration, ownership, validity period, and intended purpose before a key is placed into operational use.
  
  

• Use: Prevent unauthorized export, duplication, disclosure, reuse, or use outside approved systems and purposes.
  
  

• Logging and monitoring: Log key creation, import, export, use, administration, rotation, recovery, revocation, deletion, access failures, and policy changes where supported and relevant.
  
  

• Rotation and renewal: Define risk-based cryptoperiods and event-based rotation triggers, including compromise, personnel changes, algorithm deprecation, supplier changes, and system migration.
  
  

• Certificate management: Control certificate requests, validation, issuance, deployment, renewal, expiry monitoring, revocation, and trust-store management.
  
  

• Secret management: Prohibit hard-coded secrets and uncontrolled storage in source code, scripts, tickets, email, shared documents, or unsecured configuration files.
  
  

• Backup and recovery: Protect recoverable keys, restrict recovery access, test restoration, document dependencies, and prevent unauthorized recovery.
  
  

• Escrow: Use key escrow only where authorized and justified, with strict custody, access, recovery, and audit controls.
  
  

• Compromise response: Revoke, rotate, replace, investigate, and notify affected owners or parties according to the incident-response process.
  
  

• Suspension and revocation: Define conditions and authorization for temporarily or permanently disabling keys or certificates.
  
  

• Archiving: Retain keys only where required to decrypt legitimately retained information or verify historical signatures, with appropriate protection.
  
  

• Destruction: Securely destroy keys and all controlled copies when they are no longer required, while considering backups, replicas, escrow, caches, HSMs, suppliers, and legal holds.
  
  

• Evidence: Retain records of approval, custody, access, rotation, recovery, revocation, destruction, and verification according to the organization’s requirements.

Destroying an encryption key may make information permanently inaccessible. Therefore, key destruction should be authorized, verified, coordinated with retention and legal-hold requirements, and tested carefully where recoverability matters.

4. Monitoring, Incident Response, Assurance, and Improvement

This component ensures that cryptographic controls continue to operate effectively and that failures or weaknesses are addressed.

• Monitoring: Detect unexpected key use, failed decryption, unauthorized administrative activity, certificate expiry, configuration changes, weak protocols, and service failures.
  
  

• Alerting: Establish thresholds and escalation rules for compromise indicators, expiring certificates, inaccessible keys, cryptographic errors, and policy violations.
  
  

• Log protection: Protect relevant cryptographic logs against unauthorized access, modification, deletion, and premature disposal.
  
  

• Incident response: Define actions for suspected key disclosure, lost devices, compromised certificates, exposed secrets, ransomware, cryptographic failure, and unauthorized decryption.
  
  

• Impact assessment: Determine which systems, information, communications, backups, signatures, and third parties may be affected by a compromised key.
  
  

• Containment: Restrict access, disable affected services, revoke certificates, suspend keys, isolate systems, or block communication as appropriate.
  
  

• Recovery: Replace compromised material, restore trusted configurations, validate systems, re-encrypt information where necessary, and monitor for recurrence.
  
  

• Compliance checks: Assess configurations, certificate status, inventories, key ages, access rights, algorithm use, exceptions, logs, and supplier evidence.
  
  

• Technical testing: Test encryption, decryption, recovery, failover, rotation, revocation, certificate renewal, and destruction procedures according to risk.
  
  

• Vulnerability management: Monitor trusted sources for cryptographic weaknesses, implementation flaws, library vulnerabilities, protocol issues, and product advisories.
  
  

• Audit: Review governance, technical operation, access, evidence, exceptions, incidents, and improvement actions.
  
  

• Metrics: Track expiring certificates, overdue rotations, unapproved algorithms, failed recovery tests, exceptions, cryptographic incidents, and unresolved findings.
  
  

• Procedure review: Review the procedure at planned intervals and after significant incidents, technology changes, regulatory updates, algorithm deprecation, or major system changes.
  
  

• Training: Provide awareness to users and specialized training to administrators, custodians, developers, architects, security analysts, and responders.

Roles and Required Competence Areas

• Information Owner – classification and business risk: Determines which information requires cryptographic protection and approves business requirements.
  
  

• Information Security Manager – governance and risk: Owns the procedure, oversees compliance, coordinates reviews, and evaluates exceptions.
  
  

• Security Architect – cryptographic design: Selects appropriate patterns, validates architecture, and maintains technical standards
  
  

• Key Custodian – lifecycle control: Performs or oversees authorized key ceremonies, custody, access, recovery, rotation, revocation, and destruction.
  
  

• KMS or HSM Administrator – platform operation: Maintains cryptographic platforms, access controls, backups, configurations, availability, logging, and recovery.
  
  

• Certificate Administrator – public key infrastructure: Manages requests, validation, issuance, renewal, revocation, trust stores, and certificate inventories.
  
  

• System Administrator – implementation and maintenance: Configures encryption on servers, databases, applications, networks, backups, and devices.
  
  

• Developer – secure application implementation: Uses approved libraries and patterns, protects secrets, validates certificates, and follows secure-development requirements.
  
  

• Security Operations Analyst – detection and response: Monitors cryptographic events, investigates anomalies, and coordinates with incident responders.
  
  

• Legal and Compliance Representative – obligation analysis: Evaluates legal, contractual, signature, sector, transfer, and jurisdictional requirements.
  
  

• Supplier Owner – third-party oversight: Ensures that external cryptographic responsibilities, evidence, incidents, changes, and exit arrangements are controlled.
  
  

• User – secure handling: Uses approved encrypted services and protects devices, credentials, recovery material, and information according to instructions.

Eight Steps for Creating and Implementing the Procedure

1. Define Scope, Ownership, and Objectives

Identify the organizational units, information classes, systems, applications, networks, cloud services, devices, backups, suppliers, keys, certificates, and secrets covered. Assign the Procedure Owner, decision authorities, custodians, administrators, and reviewers.

2. Identify Requirements and Assess Risk

Review information classification, threat scenarios, risk assessments, laws, contracts, customer commitments, privacy obligations, architecture, and business needs. Determine where cryptography is required and what assurance level is appropriate.

3. Establish the Approved Cryptographic Standard

Define approved and prohibited algorithms, protocols, libraries, modules, certificate profiles, key sizes, key lifetimes, configurations, and deprecation rules. Assign a specialist owner and review schedule.

4. Design Cryptographic Architecture and Controls

Define how information at rest, in transit, in backups, on devices, in applications, and in cloud services will be protected. Document trust boundaries, key ownership, service dependencies, recovery, and supplier responsibilities.

5. Implement Key, Certificate, and Secret Lifecycle Controls

Configure approved generation, storage, access, distribution, activation, rotation, renewal, backup, recovery, revocation, archiving, and destruction processes. Maintain complete inventories and evidence.

6. Test Operation, Recovery, and Failure Scenarios

Verify encryption and decryption, key rotation, certificate renewal, backup restoration, failover, revocation, compromised-key response, provider outage, and authorized destruction before relying on the controls in production.

7. Train Personnel and Integrate Related Processes

Train relevant roles and connect cryptographic requirements to access management, change management, secure development, incident response, vulnerability management, supplier management, continuity, retention, and disposal.

8. Monitor, Audit, Review, and Improve

Monitor events and expiry dates, review access, assess compliance, manage exceptions, address incidents and findings, update technical standards, and revise the procedure when risks, technology, obligations, or systems change.

Recommended Procedure Records

• Cryptographic asset inventory: Keys, certificates, secrets, cryptographic services, owners, systems, purposes, algorithms, and status.
  
  

• Approved cryptographic standard: Approved methods, configurations, use cases, restrictions, review dates, and deprecation plans.
  
  

• Key-generation record: Request, authorization, method, platform, date, owner, custodian, and intended purpose.
  
  

• Custody and access record: Authorized roles, access grants, administrative activity, reviews, and segregation controls.
  
  

• Rotation and renewal record: Previous and new key references, date, reason, affected systems, validation, and completion evidence.
  
  

• Recovery-test record: Scenario, participants, results, issues, corrective actions, and approval.
  
  

• Revocation or destruction record: Key or certificate reference, authorization, reason, date, method, verifier, and evidence.
  
  

• Exception record: Requirement, business justification, risk, compensating controls, approver, owner, and expiry date.
  
  

• Incident record: Detection, impact, affected material, response, notifications, recovery, lessons learned, and corrective actions.
  
  

• Review record: Compliance results, technical findings, algorithm status, overdue actions, approvals, and next review date.

Benefits of Using an ISO 27001 Procedure Template

• Faster development: A structured starting point reduces drafting effort and helps identify decisions that require specialist input.
  
  

• Comprehensive coverage: The template addresses governance, technical implementation, lifecycle controls, monitoring, incidents, assurance, and training.
  
  

• Consistent operation: Teams use common requirements for cryptographic technologies and key management.
  
  

• Reduced risk: The procedure helps prevent weak methods, exposed keys, unmanaged certificates, embedded secrets, and uncontrolled exceptions.
  
  

• Improved resilience: Recovery, backup, succession, rotation, and compromise scenarios are considered before failure occurs.
  
  

• Clear accountability: Owners, custodians, administrators, developers, security teams, and suppliers have defined responsibilities.
  
  

• Better audit readiness: Controlled records demonstrate design, approval, operation, review, and improvement.
  
  

• Easier customization: The organization can align the procedure with its technologies, risks, services, obligations, and scale.

A template cannot guarantee ISO 27001 conformity. It must be adapted to the organization, approved, implemented, tested, monitored, and supported by reliable evidence.

Common Challenges and Recommended Responses

• Challenge – outdated algorithms or protocols: Response: Maintain a specialist-owned technical standard, monitor trusted guidance, and establish deprecation and migration plans.
  
  

• Challenge – keys stored with encrypted data: Response: Use approved KMS, HSM, vault, or trusted hardware solutions and apply separation of access and duties.
  
  

• Challenge – secrets embedded in code: Response: Use approved secret-management services, repository scanning, secure injection, rotation, and developer training.
  
  

• Challenge – certificate expiry causes outages: Response: Maintain inventories, automated discovery, advance alerts, ownership, renewal testing, and escalation.
  
  

• Challenge – encryption prevents recovery: Response: Design controlled key backup and recovery, test restoration, maintain succession, and verify dependencies.
  
  

• Challenge – excessive key-administrator access: Response: Apply least privilege, strong authentication, dual control, time-limited access, logging, and periodic review.
  
  

• Challenge – supplier controls are unclear: Response: Define key ownership, access, regions, notification, recovery, deletion, evidence, change, and exit requirements contractually.
  
  

• Challenge – rotation breaks applications: Response: Test rotation in representative environments, support overlapping validity, automate deployment, and maintain rollback plans.
  
  

• Challenge – destroyed keys make retained data unusable: Response: Coordinate destruction with information-retention rules, legal holds, system owners, backups, and authorized verification.
  
  

• Challenge – hard-coded technical requirements become obsolete: Response: Keep changeable algorithm and configuration requirements in a controlled technical standard referenced by the procedure.

Customizing the Procedure

The procedure should be adapted to the organization’s size, complexity, information classifications, technologies, risk appetite, suppliers, and obligations. A small organization using managed cloud services may rely on provider cryptographic capabilities, while a large organization may operate dedicated KMS platforms, HSMs, internal certificate authorities, and formal key ceremonies.

Customization should consider:

• Information and risk: Sensitivity, threat exposure, business impact, recovery needs, and data lifecycle.
  
  

• Technology stack: Endpoints, servers, networks, databases, applications, cloud platforms, backups, development tools, and operational technology.
  
  

• Cryptographic services: Provider-managed keys, customer-managed keys, HSMs, certificate authorities, vaults, and secret-management platforms.
  
  

• Applicable obligations: Legal, contractual, privacy, signature, payment, healthcare, government, or sector-specific requirements that genuinely apply.
  
  

• Operational capability: Available expertise, support models, automation, monitoring, recovery, and supplier assurance.
  
  

• Change tolerance: Availability requirements, migration complexity, certificate renewal, rotation, backward compatibility, and legacy-system constraints.

Conclusion

An ISO 27001 Encryption and Key Management Procedure provides the operational discipline required to use cryptography effectively. It helps the organization decide where encryption is needed, apply approved technical controls, manage keys and certificates throughout their lifecycle, and respond when cryptographic safeguards fail or become compromised. Organizing the procedure into four structured components creates a clear connection between governance, implementation, key lifecycle control, and ongoing assurance. Following the eight implementation steps helps ensure that cryptography is risk-based, recoverable, monitored, auditable, and integrated with related ISMS processes.