Privacy Protections to NSA Phone Surveillance

Cryptography researcher Seny Kamara, who works at Microsoft’s research lab in Redmond, Washington, has sketched out a design for such a system, called MetaCrypt. 

It would let intelligence analysts search phone records while protecting those records against leaks or unnecessary trawling. 

Kamara was inspired to develop MetaCrypt after reading about the NSA’s phone records database, which stores details of all calls made in the last five years through major U.S. communications companies such as Verizon

According to Technologyreview, several large-scale U.S. surveillance programs were revealed in documents leaked by Edward Snowden last summer, many companies and individuals have made an effort to make wider use of encryption. 

Now one Microsoft researcher says cryptography tools could also be used inside intelligence agencies to rein in surveillance, by making data stores and data searches more respectful of privacy and resistant to misuse.

MetaCrypt is a set of cryptographic protocols that could keep the information in such a database encrypted at all times. They would enforce various controls on how the information inside was used. 

The MetaCrypt design also includes a way to ensure that only approved searches are performed in the first place. Generating an encrypted search query that the data store will process requires that two analysts and at least one supervisor contribute their personal cryptographic keys. Another check is performed when it comes to decrypting the result that comes back.

Kamara’s work only shows that it’s possible to use existing encryption methods this way. Implementing MetaCrypt on a system handling large volumes of data would require significant extra work, and the end result might fall short of the performance considered practical by systems designers at a large company or government agency.

Kamara’s proposal comes at a time when the NSA’s phone surveillance program is in flux. President Obama said in January that the agency should no longer hold a domestic phone records database and suggested a third party could do so instead.

The new phone surveillance system ends up taking, ideas such as Kamara’s are unlikely to ever gain much traction in the U.S. intelligence community, says William Binney, a former NSA analyst and cryptographer who has been a vocal critic of the agency since retiring in 2001.

Author Venkatesh Yalagandula Follow us Google + and Facebook and Twitter