If a company maintains its own encryption keys, the government will need to make a legal request for the keys with the company and not the cloud provider, he said. Otherwise, all they would get from the cloud provider would be "encrypted useless gibberish," he said. "This puts the power of ownership back into the hands of businesses."
Richard Moulds, vice president of product strategy at Thales E-security said reports on the NSA's surveillance activities have heightened concerns over encryption key ownership in the cloud. "People are now beginning to ask 'why should I trust the cloud provider to look after the encryption keys?' " he said.
In theory, encrypting everything in the cloud is a great way to protect data from prying eyes, he said. [But] "key management is the Achilles heel of all cryptographic systems," Moulds said. "When you think about doing encryption in the cloud, who is going to own the keys?"
The problem with persistent encryption in the cloud is finding a way to make sure that all parties that require access to the encrypted data have the keys for decrypting it as needed, said John Pescatore, director of emerging security trends at SANS Institute.
"Encrypting data is easy, making sure the intended recipients, and only the intended recipients, can decrypt it" is challenging, he said.
Companies need to either find a way to make the decryption keys available as required or entrust a third party to distribute the keys in a secure fashion. "The former is expensive and hard to scale, the latter doesn't exist," Pescatore noted.
"For persistent encryption to work there has to be a trusted third party. But if you worry about government surveillance, you can't trust any third parties," which means being prepared to deal with a costly and complex in-house effort, he said.
Pravin Kothari, CEO of CipherCloud, compared most cloud encryption approaches to locking a car and leaving the key right next to the parked car. For companies to truly exercise control over their cloud data, some fundamentally new approaches are needed, he said.
CipherCloud for instance, offers a gateway technology that lets companies encrypt data while it is in transit to the cloud and while it is stored there. The gateway allows enterprises to store their encryption keys locally, while allowing users to interact with the encrypted data in the cloud with none of the usual key distribution issues.
There's also the question of whether the effort is truly necessary. Reports of the NSA's surveillance activities spurred widespread privacy concerns, but there's little to show that corporate data is at any risk.
"One of the best ways to protect data is to hold the keys to your encrypted data," said Lawrence Pingree, an analyst with research firm Gartner. But the whole NSA spying issue is overblown, at least in terms of its impact on corporate data in the cloud, he said. So far, there has been no evidence that has been publicly disclosed at least showing that the government has misused the data it has gathered or to which it has access.
"The focus on nation-state actors is overblown hype since the majority of data that is misused is from other threat actors such as organized crime, fraudsters and industrial espionage," Pingree said.
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