Key Elements of Information Backup Policy as per ISO 27001:2022: A detailed Guide in 2023
- jai sisodia
- Oct 13, 2023
- 6 min read
Updated: Oct 23, 2023
Table of Contents
Defining Information Backup
Information backup refers to the process of copying and archiving data and information so that it can be restored in the event of data loss.
The primary purpose of a backup is to provide a way to recover data after its loss, be it by data deletion, corruption, hardware failures, or other adverse events.”
Information backup involves creating and storing copies of information, software and system images in a secure location, separate from the original source. The backup copies should be protected from unauthorized access, modification or deletion, and should be tested periodically to verify their usability and completeness.
It is a “Corrective” control that ensures Integrity and Availability of the relevant Information.
ISO 27001:2022 Reference: Annex 8.13 Information Backup of ISO 27001:2022 provides guidance on how to implement the ISO 27001:2022 compliant control on Information Backup.
Key Elements of Information Backup Policy as per ISO 27001:2022
Let's delve into the key elements that constitute a comprehensive backup plan or policy, based on the guidance provided in ISO/IEC 27001:2022
1. Backup and Restoration Procedures
A Backup plan should be able to produce and complete records of the backups and documented restoration procedures.
2. Identify the Backup Requirements
The backup requirements should be based on the business impact analysis (BIA), Risk Assessment and Contractual Obligations
2.1 Business Impact Analysis
Business Impact Analysis (BIA) is a foundational element of Business Continuity Planning, focusing on identifying critical business functions and assessing the potential effects of interruptions. Through BIA, organizations can determine their:
Recovery Time Objective (RTO): The maximum acceptable downtime for a function post-disruption — and their
Recovery Point Objective (RPO): The Maximum data loss acceptable
By evaluating the potential impact over time, understanding data dependencies, considering regulatory requirements, and engaging with stakeholders, businesses can set informed RTOs and RPOs, ensuring alignment with organizational priorities.
BIA identifies and quantifies effects of business function interruptions.
RTO defines the maximum acceptable downtime post-disruption.
RPO determines the maximum acceptable data loss.
Impact assessment over time frames helps set RTO.
Data dependency evaluation aids in defining RPO.
Stakeholder input and regulatory requirements refine RTO and RPO values.
Regular reviews and tests ensure RTO and RPO remain relevant and achievable.
Other factors that can be used to derive Business requirements are:
Availability and capacity of the backup media and infrastructure
Compatibility and interoperability of the backup software and hardware.
3. Backup Operations
This includes several key areas:
3.1 Backup Methods
1. The backup methods should be appropriate for the type, format and size of the information to be backed up, as well as the frequency and speed of the backup process.
2. The backup methods may include full backup, incremental backup, differential backup, mirror backup, snapshot backup or online backup.
Full Backup: This involves copying all the data in a system. It provides the most comprehensive backup but can be time-consuming and storage intensive.
Incremental Backup: Only the changes made since the last backup (whether it was a full or incremental backup) are copied. This is faster and requires less storage than a full backup but may require a longer restoration process.
Differential Backup: This backs up all the changes made since the last full backup. It's a middle ground between full and incremental backups in terms of speed and storage.
Mirror Backup: This creates an exact copy of the source data. Any deletions in the source are also mirrored in the backup.
Snapshot Backup: This captures the state of a system at a particular point in time.
3. The backup methods may also involve compression, deduplication or encryption techniques to reduce the storage space and enhance the security of the backup copies.
Compression: Compression is a method used to reduce the size of data. By using algorithms to eliminate redundant data or represent data in a more efficient manner, compression can significantly reduce the amount of storage space required for backups. This not only saves on storage costs but can also speed up the backup and restore processes.
De-duplicaton: Deduplication involves eliminating duplicate copies of repeating data within the backup process.
For instance, if multiple departments have saved the same file, instead of storing that
file multiple times, deduplication ensures it's stored once, with references pointing to the single copy. This conserves storage space and can make backups more efficient.
Encryption: Encryption is the process of converting data into a code to prevent unauthorized access.
When data is backed up, especially if it's being sent to an off-site location or stored in the cloud, there's a risk of interception or unauthorized access. Encryption scrambles this data, making it unreadable without the correct decryption key. This ensures that even if someone were to gain access to the backup data, they wouldn't be able to understand or use it without the decryption key.
3.2 Backup Logging and Monitoring
The backup operations should be monitored and logged to ensure their completion and accuracy. The backup operations should also be audited and reviewed regularly to ensure their compliance with the backup policy and standards.
4. Backup Security
4.1 Physical and Environmental Security of Backups
Physical and environmental protection of backups is crucial to ensure the integrity and availability of the data. If backups are compromised due to environmental factors or physical threats, it defeats the purpose of having them in the first place. Here's a breakdown of why and how to provide such protection:
4.1.1 Why Physical and Environmental Protection is Essential?
Data Integrity: Physical damages, such as those caused by fire, water, or excessive heat, can corrupt backup data, rendering it useless during a recovery process.
Data Security: Physical theft or unauthorized access to backup media can lead to data breaches, especially if the data isn't encrypted.
Data Availability: In the event of a disaster, having backups that are readily available and in good condition is crucial for business continuity.
4.1.2 How to Ensure Physical and Environmental Protection?
1. Secure Storage
Store backups in a secure location with restricted access to prevent unauthorized personnel from accessing or tampering with them.
Use lockable storage cabinets or safes for critical backup media.
2. Fire Protection
Use fire-resistant safes or vaults for storing backup media.
Install fire suppression systems, preferably those designed for data centers or storage areas, which don't use water as it can damage electronic media.
3. Climate Control
Maintain a stable temperature and humidity level in the storage area. Extreme temperatures and humidity can degrade backup media over time.
Use air conditioning, dehumidifiers, or other climate control equipment as necessary.
4. Protection from Electromagnetic Interference:
Store backups away from equipment that produces electromagnetic fields, as these can corrupt or erase data on certain types of backup media, especially tapes.
5. Elevated Storage
Store backup media off the ground to protect against potential water damage from flooding or leaks.
6. Regular Inspection
Periodically inspect the physical condition of backup media for signs of wear, damage, or degradation.
Rotate and replace media as necessary.
7. Off-site Storage
Store copies of backups in a separate, secure location away from the primary business site. This ensures data availability in case of a site-specific disaster.
Ensure the off-site storage facility also adheres to the same physical and environmental protection standards.
8. Transportation:
If backups are transported (e.g., to an off-site location), use protective cases and trusted couriers. Ensure the transportation environment is also controlled.
4.2 Backup Encryption
Backup encryption is a critical aspect of data protection. When data is backed up, especially if it's being transported or stored off-site, it becomes vulnerable to theft, interception, or unauthorized access.
Encrypting backups ensures that even if the data falls into the wrong hands, it remains unreadable and secure.
4.2.1 Why Backup Encryption is Important?
Data Security: Encryption ensures that unauthorized individuals cannot read or misuse the data, even if they gain access to the backup media or files.
Regulatory Compliance: Many industries have regulations that mandate the protection of sensitive data, including its backup. Encryption helps businesses meet these regulatory requirements. This is obviously a requirement in ISO 27001:2022 as well
Protection During Transit: If backups are being transported, especially over the internet to cloud storage or another off-site location, they can be intercepted. Encryption ensures the data remains confidential during transit.
Peace of Mind: Knowing that backups are encrypted provides peace of mind that the data is safe, even in worst-case scenarios like theft or data breaches.
4.2.2 Backup Encryption: Best Practices
Choose Strong Encryption Algorithms: Use industry-recognized encryption standards like AES (Advanced Encryption Standard) with a key length of at least 256 bits.
Key Management: The strength of encryption largely depends on the secrecy and complexity of the encryption keys. Ensure:
o Keys are stored securely, separate from the encrypted backups.
o Regular rotation of encryption keys.
o Use of hardware security modules (HSMs) or key management services for added security.
End-to-End Encryption: Ensure that data is encrypted at the source (before it leaves the original location), remains encrypted during transit, and stays encrypted at the backup destination.
Regular Audits: Periodically review and audit encryption practices to ensure they remain up to date with current threats and best practices.
Test Restores: Regularly test restoring from encrypted backups to ensure that data can be decrypted and accessed when needed.
4.3 Test and Verify Backup Copies
The backup copies should be tested and verified periodically to ensure their usability and completeness.
The testing and verification procedures may include restoring or recovering the backup copies to a test environment, checking the integrity and consistency of the data, comparing the source and destination files or folders, or performing a checksum or hash calculation.
The testing and verification results should be documented and reported to the relevant stakeholders.
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