As long as IT managers encrypt data using only one vendor's products, the keys used to decrypt that data can be relatively easy to manage. But it will likely become much more complicated as more vendors build encryption into more and different types of storage devices, each with their own key management system, and as users need to move encrypted data among devices for disaster recovery, legal discovery or simply everyday business communications.
"If you share the key, you share the data; if you lost the key, you've lost the data," says Dennis Hoffman, general manager of the data security unit of RSA Security, now owned by EMC. The fear of losing decryption keys (and thus their data) has kept many organizations from encrypting stored data. But faced with regulations requiring that customer data be kept safe, and the prospect of hefty fines and bad publicity when backup tapes are lost, more and more companies are encrypting stored data. Another factor, security experts say, is that if the data on a lost or stolen tape or disk drive has been encrypted, the company that owns the data often isn't required to report the loss.
While in the past encryption usually required a standalone appliance, vendors including IBM, Sun Microsystems and Spectra Logic offer tape libraries with built-in encryption capabilities. In October, Seagate Technology announced it will include Full Disk Encryption (FDE) technology in all its enterprise-class drives, and vendors such as Oracle offer encryption in their databases.
That blizzard of encryption, and of keys, calls for a single, unified approach that puts "all the keys to the kingdom all in one place and managed, ideally, by one group in the organization," says Richard Moulds, vice president of nCipher Corp. Ltd., a security hardware and software vendor. Whether or not the storage group is in charge of key management, experts say, they need to understand how key management works and where storage keys fit into the big picture.
Encryption converts plain text into unreadable form, and keys are numbers which are used by an algorithm to either encrypt or decrypt data.
In symmetric encryption, the same key is used for both encryption and decryption. Asymmetric encryption, also called public key encryption, employs two keys, one public and one private, and is often used to encrypt communication over unsecure channels such as the Internet. In public key encryption, the sender uses the recipient's public key (to which they have access) to encrypt the data, and the recipient uses their private key (to which only they have access) to decrypt it.
To assure the authenticity of the public keys, many organizations deploy a public-key infrastructure, or PKI, which consists of a certificate authority that issues and verifies digital certificates. The certificates identify an individual or organization and include the public key or information about it. PKIs also include a registration authority that verifies the certificate before it is issued, a directory to store the certificates and a system for managing the certificates.
The key management systems found in most tape encryption systems "are fairly automated and (the customer doesn't) have to worry about it too much," says Walt Hubis, a software architect at LSI Logic and chair of the key management services subgroup at the Trusted Computing Group, a non-profit security standards organization.
But key management will become more complex, experts say, as encryption finds its way into more and more storage devices, in addition to the existing encryption used in networks and in applications such as databases.
Depending on the complexity of a company's environment, a management system may need to control which users, applications can create and destroy keys, send and receive keys and determine how long keys will remain in effect. Some keys (such as those used to encrypt data in transit) only have a lifecycle of a second or so, says Hubis, while others that protect medical data must be maintained for 20 years or more. In addition to managing keys for encrypting and decrypting data, a management system might also need to handle the keys used to encrypt and decrypt the keys themselves.