Data that resides in QoreStor can be encrypted. When encryption is enabled, QoreStor uses the Industry standard FIPS 140-2 compliant 256-bit Advanced Encryption Standard (AES) encryption algorithm for encrypting and decrypting user data. The content encryption key derives from the passphrase, which you assign to a specified storage group, and is managed by the key manager, which operates in either a Static mode or an Internal mode. In Static mode, a global, fixed key is used to encrypt all data. In internal mode, key lifecycle management is performed in which the keys are periodically rotated. The minimum key rotation period before the content encryption key can be rotated and a new key is generated is 7 days. This rotation period is user-configurable and can be specified in days.
A user-defined passphrase is used to generate a pass phrase key, which is used to encrypt the content encryption keys. It is mandatory to define a passphrase to enable encryption. The system supports up to a limit of 1023 different content encryption keys. All streams of a data-store are encrypted or re-encrypted with the same content encryption key. QoreStor statistics report the amount of data encrypted and decrypted bytes consistently.
This topic introduces and briefly defines some basic encryption at rest terminology used in QoreStor documentation.
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Passphrase |
A passphrase is a sequence of words or other text used to control access to data, similar to a password in usage, but is generally longer for added security. The QoreStor passphrase is user-defined and is used to generate a passphrase key that encrypts the file in which the content encryption keys are kept. The passphrase is a human readable key, which can be up to 255 bytes in length. It is mandatory to define a passphrase to enable encryption. |
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Content encryption key |
The key used to encrypt the data. The content encryption key is managed by the key manager, which operates in either a static mode or an internal mode. The system supports up to a limit of 1023 different content encryption keys. |
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Key management mode |
The mode of key lifecycle management as either static or internal. |
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Static mode |
A mode of key management in which a fixed key is used to encrypt all data and is global for each storage group, which lets you configure static mode for one storage group and internal mode for another storage group. |
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Internal mode |
A mode of key lifecycle management in which the keys are periodically generated and rotated. The minimum key rotation period before the content encryption key can be rotated and a new key is generated is 7 days. This rotation period is user-configurable and can be specified in days. |
This topic describes key features and considerations of using Encryption at Rest in QoreStor.
- Key Management — In internal mode there is a maximum limit of 1023 keys. By default when encryption is enabled on the system, the key rotation period is set to 30 days. Users can later change the key rotation period from 7 days to 70 years, while configuring internal mode of encryption.
- Performance Impacts — Encryption should have minimal to zero impact on both backup and restore workflows. It should also have no impact on the replication workflows.
- Replication — Encryption must be enabled on both the source and target QoreStor systems to store encrypted data on the systems. This means that encrypted data on the source does not automatically imply that when it is replicated to the target it will be encrypted unless encryption is explicitly turned ‘ON’ on the target QoreStor system.
- Security Considerations for Passphrase and Key Management —
- A passphrase is very important part of the encryption process on the QoreStor system as the passphrase is used to encrypt the content encryption key or keys. If the passphrase is compromised or lost, the administrator should change it immediately so that the content encryption keys do not become vulnerable.
- The administrator should closely consider security requirements to drive the decision for selecting the mode of key management for the QoreStor system.
- The Internal mode is more secure than the Static mode since the keys are periodically changed. Key rotation can be set to 7 days minimum.
- Key modes can be changed at any time during the lifetime of the QoreStor system; however, changing the key mode is a significant operation to undertake as all encrypted data must be re-encrypted.
- Content encryption keys are stored in their encrypted form in a primary keystore, which is maintained on the same enclosure as the data-stores. For redundancy purposes, a backup copy of the primary keystore is stored on the system in the root partition, separate from the data-store partitions.
The overall steps for how Encryption at Rest is enabled and used in QoreStor are described below.
- Enabling encryption.
Encryption is disabled by default on QoreStor. An administrator can enable encryption by using the GUI or CLI.
Encryption is set at the storage group level.
- Setting a passphrase and setting the mode.
When defining encryption for a storage group, a passphrase is set. This passphrase is used to encrypt the content encryption keys, which adds a second layer of security to the key management. At this time, the mode is also set. The default key management mode is “internal” mode, in which key rotation happens periodically as specified by the set key rotation period.
- Encryption process.
After encryption is enabled, the data in the storage group that gets backed up is encrypted and is kept encrypted until it is expired and cleaned by the system cleaner. Note that the encryption process is irreversible.
- Encryption of pre-existing data.
Any pre-existing data will also be encrypted using the currently set mode of key management. This encryption occurs as part of the system cleaner process. Encryption is scheduled as the last action item in the cleaner workflow. You must launch the cleaner manually using the maintenance command to reclaim space. It then encrypts all pre-existing unencrypted data. The cleaner can also be scheduled as per the existing pre-defined cleaner schedule.
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NOTE: The cleaner can take some time to start the encryption process if the system is nearing full system capacity. Encryption starts only after the cleaner processes data slated for cleaning and the related logs. This ensures that space reclamation is prioritized when free space is low and also ensures that data stores are not redundantly encrypted. |
Refer to theQoreStor Command Line Interface Reference Guide for information about the CLI commands used for encryption.
