Microsoft is attacking Google for misleading customers about the security certification of a suite of software programs for governments.

Microsoft's deputy general counsel, David Howard, blogged on Monday about a newly unsealed court document that shows that "Google Apps for Government" hasn't been certified under the Federal Information Security Management Act.

According to the court documents, the United States Department of Justice had rejected Google?s claim that Google Apps for Government, Google?s cloud-based suite for government customers, has been certified under the Federal Information Security Management Act (FISMA).

"Given the number of times that Google has touted this claim, this was no small development," Howard commented.

Last year, the Department of the Interior selected Microsoft offerings for its new cloud-based email system. In October, Google responded by suing the Government. Google announced its lawsuit with a proclamation of support for "open competition." It then touted the security benefits of Google Apps for Government. Google filed a motion for a preliminary injunction telling the court that Google Apps for Government is certified under FISMA.

Microsoft accuses Google for insisting that "Google Apps for Government have earned the FISMA certification."

FISMA certification suggests that a particular information management system such as an e-mail solution meets an adequate level of security for a specific need.

On Friday afternoon and according to some of the court papers, a statement by the Department of Justice contradicting Google on one of its basic FISMA claims. The DOJ?s brief says "On December 16, 2010, counsel for the Government learned that, notwithstanding Google?s representations to the public at large, its counsel, the GAO and this Court, it appears that Google?s Google Apps for Government does not have FISMA certification."

Google claims that it's not deceiving anyone, since a less-robust version of the product has already been certified under FISMA. Google added that "Google Apps" received a FISMA clearance in July 2010, and that "Google Apps for Government" is "the same system with enhanced security controls that go beyond FISMA requirements."

But the Justice Department acknowledged that the General Services Administration (GSA) had certified a different Google offering, Google Apps Premier, for its own particular use under FISMA last July.

However, the DOJ?s brief explains, "Google intends to offer Google Apps for Government as a more restrictive version of its product and Google is currently in the process of finishing its application for FISMA certification for its Google Apps for Government." The brief adds, "To be clear, in the view of the GSA, the agency that certified Google?s Google Apps Premier, Google does not have FISMA certification for Google Apps for Government."

"Google can?t be under the misimpression that FISMA certification for Google Apps Premier also covers Google Apps for Government. If that were the case, then why did Google, according to the attachments in the DOJ brief, decide to file a separate FISMA application for Google Apps for Government?" Microsoft's counsel wrote on Microsoft's blog.

The controversy between Microsoft and Google continues. Last February, Google accused Microsoft of copying Google's search results. Later, Microsoft filled a first formal antitrust complaint against a rival by arguing to European authorities that Google is abusing its dominance to freeze out rival services.