Data Encryption - FAQ

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Table of Contents

General

How can I tell if a job has been encrypted and by what method?

What kind of performance hit can I expect from encryption?

Which is the most secure encryption algorithm?

Can I encrypt NDMP data during backup or auxiliary copy?

Does Encryption require a Certificate Authority?

What is the cryptographic library used?

What is the AES block mode of operation and IV management for encrypted data?

What integrity checks are performed on encrypted data?

Where does Decryption occur?

How are User passwords encrypted, transmitted, and stores?

What happens to encrypted data if you uninstall the license?

Auxiliary Copy

Does Calypso Monitor software encrypted data stay encrypted during auxiliary copy?

Where does Offline/Auxiliary copy encryption occur - at the source or target MediaAgent?

Is Offline/Auxiliary copy Encryption supported on all MediaAgent host operating systems?

If I enable encryption during both backup and offline/auxiliary copy – is the data encrypted twice?

Hardware

If hardware encryption is enabled – will this further encrypt already encrypted data?

Can I restore hardware encrypted data using Media Explorer?

Does hardware encryption require a License?

What Encryption-capable tape drives are supported?

What happens to jobs if Hardware encryption is selected but the drive does not support it?

Do we support any third party encryption hardware?

Can Bull Calypso set the Encryption algorithm and key length for hardware encryption?

Keys

How keys are derived?

What is the ANSI 9.31 implementation?

Is a persistent seed used for the random number generator?

How often are keys changed for each system?

How are keys integrity checked?

How are keys identified?

How are keys authenticated?

How are keys stored in the CommServe database?

If someone had access to the CommServe database could they use the keys to decrypt data?

Are keys stored anywhere else?

How are keys backed up for disaster recovery purposes?

Who has access to the encryption keys?

How are keys destroyed when they are no longer needed?

Pass Phrase

When would I use a Pass Phrase?

Can I change the Pass Phrase?

How are Pass Phrases used to authenticate a restore?

Where are Pass Phrases stored?

Can I restore Pass Phrase protected data using the Command Line Interface?


General

How can I tell if a job has been encrypted and by what method ?

The Jobs in Storage Policy report will show a superscript E or an HE next to the job ID for jobs that have been software or hardware encrypted respectively.

What kind of performance hit can I expect from encryption?

Software encryption is a CPU intensive operation and can reduce your backup or auxiliary copy performance by an estimated 40%-50%.

Hardware encryption has a significantly less impact of about 10%.

Which is the most secure encryption algorithm?

RijnDael, by virtue of it being the Advanced Encryption Standard (AES), would be considered the most secure encryption algorithm; However, AES was selected based on a series of requirements of which security level was just one. All candidates for AES met or exceeded the security requirement. Serpent and Twofish ciphers were also AES candidates. Twofish is faster and Serpent is considered more secure.

Can I encrypt NDMP data during backup or auxiliary copy?

If the NDMP data is directed to a NDMP Remote Server-enabled MediaAgent for data protection or auxiliary copy you can software and hardware encrypt the data. For NDMP data sent directly to a filer-attached library only hardware encryption is supported. Filer direct Hardware encryption requires a 3rd party key management system.

Does Encryption require a Certificate Authority?

Certificate Authority is required only for Asymmetric cryptography where different keys are used to encrypt (using private key) and decrypt (using public key) the data. All of our encryption is symmetric cryptography (the same key is used to encrypt and decrypt) ,so there is no need for a certificate or a certificate authority.

Asymmetric crypto is typically used when you are sending data over insecure lines (like over the internet) and the identity of entities at each end is not known, the CA helps validate the authenticity of that sent data so that malicious data is not sent. In our case, since there are known entities at both ends this issue does not exist.

We do not encrypt data set with a single key. Instead we generate a key for every chunk of data that is written which means there is an extremely minimal chance of the entire data being lost even if one key is compromised.

What is the cryptographic library used?

CommVault Cryptographic Library Version – 1.0 (FIPS 140-2 Certified)

What is the AES block mode of operation and IV management for encrypted data?

AES 256 - CBC mode. Each 64KB block is a single CBC chain. IVs are randomly generated using a ANSI 9.31 random number generator. There is no extra special management of IVs. They are included into the ciphertext stream.

What integrity checks are performed on encrypted data?

Integrity for each up-to-64KB encrypted data block is checked with CRC32.

Where does Decryption occur?

Type of encrypted data Decryption will occur on:
Hardware Hardware device
Software
  • At the client upon restore
  • On the source MediaAgent during synthetic full (decrypted/re-encrypted automatically)
  • On the source MediaAgent during auxiliary copy of deduplicated data (re-encryption on the Source MediaAgent is an option requiring the offline encryption license)
  • On the source MediaAgent during auxiliary copy if re-encryption is selected. (decrypted then re-encrypted with select algorithm)
  • On the Media Explorer host when restoring data
 

How are User passwords encrypted, transmitted, and stores?

Bull Calypso user passwords are encrypted using a proprietary algorithm and transmitted/stored only in encrypted format. External (Active Directory) user passwords are not stored.

What happens to encrypted data if you uninstall the license?

Existing data remains encrypted and can be recovered. New data will not have the option for encryption.

Auxiliary Copy

Does Calypso Monitor software encrypted data stay encrypted during auxiliary copy?

Yes, source or primary encrypted data remains encrypted for all subsequent copies within the storage policy. However, if the auxiliary copy source is an encrypted dedupe store then data encrypted as part of the dedupe process will be decrypted by an auxiliary copy job. In this case, if you want to retain encryption then Offline encryption must be enabled on the destination copy.

Offline encryption which can be configured to occur during auxiliary copy also allows you to retain the existing cipher method – or use an alternate cipher method

Where does Offline/Auxiliary copy encryption occur - at the source or target MediaAgent?

Offline Encryption performed during an auxiliary copy operation is performed at the source MediaAgent. This provides transmission path security.

Is Offline/Auxiliary copy Encryption supported on all MediaAgent host operating systems?

No, the Netware MediaAgent does not support auxiliary copy encryption.

If I enable encryption during both backup and offline/auxiliary copy – is the data encrypted twice?

No, the data is not encrypted twice. Data that has been encrypted by Calypso Monitor software is flagged. During an auxiliary copy operation the flag is checked and, if the data has already been encrypted, no additional software encryption is applied. Only data that has not been encrypted by Bull Calypso will be encrypted during the auxiliary copy process.

Hardware

If hardware encryption is enabled – will this further encrypt already encrypted data?

Yes, software encrypted data will be further encrypted if hardware encryption is enabled. We strongly recommend enabling one or the other – not both.

Can I restore hardware encrypted data using Media Explorer?

Yes, Media Explorer supports restore of hardware encrypted data from a supported drive.

Does hardware encryption require a License?

Encryption licensing is broken up into following parts:

License Type Provided for Applied at
Data Encryption
  • Primary data protection encryption
  • Key management
  • Hardware encryption
The CommCell® level for all client data.
Auxiliary Copy Encryption Secondary copy encryption during the auxiliary copy operation The MediaAgent level and is required for each destination MediaAgent performing Offline Encryption.

What Encryption-capable tape drives are supported?

Bull Calypso software currently supports only LTO-4 encryption capable tape drives. Refer to Hardware Encryption for more details.

What happens to jobs if Hardware encryption is selected but the drive does not support it?

The Hardware encryption option is enabled on the Storage Policy copy as a property of the data path. Hardware encryption is only applicable for supported Tape Devices. If the drive does not support hardware encryption and the option is selected, backups running to the drive will fail.

Do we support any third party encryption hardware?

Hardware encryption devices with their own key management software such as Network Appliances (formerly Decru’s) Datafort can be used. These inline devices are transparent to the data flow from Bull Calypso. However, data written via these devices must be restored via these devices and it is the customer’s responsibility to provide and manage these devices.

Can Bull Calypso set the Encryption algorithm and key length for hardware encryption?

No, hardware encryption algorithm and key length is fixed by the hardware vendor. Most of tem use AES-256 for FIPS compliance. Bull Calypso can enable or disable hardware encryption. Any variance to algorithm or key length used is hardware vendor dependent.

Keys

How keys are derived?

Keys are generated from a random number generator. The random number generator we use is ANSI 9.31 It’s used to produce RSA key pair for the client, generate random 128-bit or 256-bit data encryption keys for every chunk and initial vectors (IV) for CBC chaining during data encryption.

What is the ANSI 9.31 implementation?

ANSI 9.31 is the standard for digital signatures based on the RSA algorithm. It requires the MDC-2 hash algorithm.

Refer to http://csrc.nist.gov/groups/STM/cavp/documents/rng/931rngext.pdf for more information.

Is a persistent seed used for the random number generator?

No. Various random OS-supplied data is used.

How often are keys changed for each system?

We generate a different random 128 or 256 key for every chunk we write. Each job can contain multiple chunks, so each backup job can have multiple randomly generated keys. With multiple different keys the strength of the encryption is very high.

How are keys integrity checked?

Every key stored in the Database has CRC32 embedded. This is used only to check whether a key has been entered incorrectly. If an error is detected the user will be prompted to re-enter the pass phrase or check for network/media corruption.

How are keys identified?

Keys are identified by their storage location in the database. We don’t embed IDs into the keys.

How are keys authenticated?

They are wrapped using AES Key Wrap Specification.

Refer to AES Key Wrap Specification for more details.

How are keys stored in the CommServe database?

Data encryption keys are stored in the database encrypted with RSA public key of the client. RSA private key of the client is stored encrypted either with a built-in pass-phrase or with the pass-phrase provided by user, depending on the settings.

If someone had access to the CommServe database could they use the keys to decrypt data?

If the data is encrypted:

Are keys stored anywhere else?

Keys can optionally be written to the backup media for manual recovery of data using Media Explorer.

How are keys backed up for disaster recovery purposes?

A regularly scheduled Export and Backup of the CommServe Database (DR Backup task) provides Disaster Recovery protection.

Who has access to the encryption keys?

No users are allowed access to the keys. Our keys are stored in the CommServe Database encrypted with RSA public key of the client. RSA private key of the client is stored encrypted either with a built-in pass-phrase or with the pass-phrase provided by user, depending on the settings. The user provided Pass Phrase is not stored anywhere. Only authorized users (configured from user management) can set and change these pass phrases. Pass phrases are never displayed in clear text.

How are keys destroyed when they are no longer needed?

When chunks are pruned (erased), the database entry and associated key for that chunk is deleted. Open keys in memory are deleted using memset().

Pass Phrase

When would I use a Pass Phrase?

A Pass Phrase can be enabled and set differently for each client providing unique protection of the encryption keys for data .For example; you may want to provide unique Pass Phrases for certain financial data servers and personnel file servers. When restoring Pass Phrase encrypted data, you must manually provide the Pass Phrase. If you lose the Pass Phrase, the encrypted data is unrecoverable.

Can I change the Pass Phrase?

Yes, you can change the Pass Phrase at anytime. You do not need to maintain the older Pass Phrase. Since a Pass Phrase can only be used for CommCell® recovery of encrypted data, the latest version of the Pass Phrase cannot be used to decrypt all previous Pass Phrase protected data.

How are Pass Phrases used to authenticate a restore?

They are used to decrypt the RSA private key of the client. The RSA private key is then used to decrypt the chunk keys. Chunk keys are used to decrypt the data.

Where are Pass Phrases stored?

Pass phrases are not stored. Pass phrase must be entered manually by the user for each recovery. However, by creating and exporting a file that contains the scrambled pass-phrase of the client computer to a dedicated directory on another computer, the system can recover the client's data to that (and only that) computer without prompting for the pass-phrase.

Can I restore Pass Phrase protected data using the Command Line Interface?

Yes, by exporting the pass phrase to the target client then use the normal Command Line Interface restore process to recover the data.

Refer to Export an Encryption Pass Phrase for more details.


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