RSA 2014 Microsoft's isn't involved in mass spying or putting backdoors in its software, Redmond's VP of Trustworthy Computing Group Scott Charney told the RSA conference. Why? Because it's unethical and bad for business, he said.

"We've not been concerned about the Snowden disclosures because we've been principled," he said. "We do defense, not offence. We never do bulk data collection."

Charney said that Microsoft was happy to help law enforcement – up to a point. It has the Computer Online Forensic Evidence Extractor (COFEE) tool which can be installed on a USB key and used to investigate Microsoft systems. But Redmond would not participate in illegal searches, Charney said, and would fight in the courts against such orders.

He also denied that Microsoft was putting backdoors into code. He mentioned the NSA Key saga, when in 1999 a researcher found an encryption key in Windows NT called _NSAKEY. Microsoft has always maintained that the key was so named because the NSA oversaw encryption export controls, and Charney reaffirmed that today – commenting that if Microsoft had put a backdoor in its code, it wouldn't have called it NSA Key.

"If I put a backdoor in our product, our market capitalization goes from $260bn to zero overnight. I can't even sell it. It's nuts! Economic suicide! So no backdoors," he said.

In order to reassure foreign governments that Microsoft's code is secure from such shenanigans, Redmond makes its source code available to other country's governments for checking. If they find flaws, they are fixed at Microsoft, but it's another way of reassuring customers, Charney said.

Charney echoed Art Coviello's call for a ban on software weaponry, saying that it was counterproductive to all concerned and had a huge potential for blowback damage on the sender, since it always leaks out.

He cited Stuxnet as a case in point. The code may have slowed down Iran's efforts to process uranium, but the software itself was picked up by researchers and malware authors and examined. The Stuxnet code used multiple zero-day attacks to get its job done, and as a result millions of computer users were put at risk and had to update their systems.

While Charney is obviously sincere in his beliefs that Microsoft is on the side of the angels, others are less sure.

"The best Microsoft can say is that we are secure except for the vulnerabilities that we don't know about and the ones we are prohibited by law from telling you about," security expert and CTO of CO3 Bruce Schneier told The Register.

"This is the problem. Microsoft might be 100 per cent truthful about this, but they have no way of proving it. Because the NSA has poisoned the environment, we have no reason to believe them." ®