SECURING FIBRE CHANNEL FABRICS - Brocade

Brocade Encryption FeaturesThe next encryption process to consider is the rekey operation, inwhich a LUN is re-encrypted using a different key. There are two basicreasons why a rekey operation would be performed: a compromisedkey or a security policy requirement. If a key is lost or stolen, it is compromisedand the data encrypted with this key can no longer beconsidered secure. The security or risk management department of anorganization may implement a policy requiring that all keys must berefreshed on a specified schedule, such as every 36 months. This isoften done out of fear that keys may have been compromised withouttheir knowledge and the organization may prefer to err on the side ofcaution by forcing a rekey of all encrypted data after a defined periodof time. However, most of the time, the primary reason organizationsperform a rekey operation is that they are mandated to do so as aresult of a compliance requirement, such as with the PCI-DSS. Rekeyingcan be performed automatically by setting an expiration date on akey using the Brocade encryption device, but this is not generally recommended.It is preferable to expire keys manually to control exactlywhen this is performed and schedule off-peak hours.In-place rekeying is not possible for tape, since a tape drive is a steamingdevice and the media itself is flexible. Rekeying data on a tapeinvolves copying it to a new tape and encrypting it with a different keyas the data is copied. In the case of disk media, the process is muchsimpler, since the LUN with the compromised key can be rekeyed inplaceand online if necessary.During the rekey operation, the LUN actually has two keys assigned toit, one used for new writes and one for reading data that has not yetbeen rekeyed. Once the rekey process is completed, the original key isno longer used. As with a first-time encryption, the rekey operation canbe performed online or offline.Clustering and AvailabilityOne of the principle tenets of security is maintaining availability. Needlessto say, downtime can be expensive and precautions must betaken to prevent a loss of availability of the information. This is particularlytrue for encryption solutions, since there is a completedependence on the encryption keys to recover encrypted information.Compounding this problem is the importance of the applications thatrequire encryption. Any loss of availability of information that is importantenough to require encryption is mostly likely to be disastrous forits owners. Extensive precautions must be taken to protect the keysand to maintain the availability of the encryption solution.Securing Fibre Channel Fabrics 181