Heavyweights of the cryptographic world have lined up behind a campaign against proposed US wiretapping laws that could require IT vendors to place new backdoors in digital communications services.
Technical details are vague at present, but the planned law could mandate putting wiretap capabilities in endpoints to cover everything from instant messaging and chat to services such as Skype, Google Hangouts and even Xbox Live.
The plan to update the Communications Assistance for Law Enforcement Act (CALEA) comes as part of proposals to update US wiretapping laws drafted in the 1990s, which were designed to apply to telephone exchanges and switching equipment.
Critics of the proposed law - including cryptographer Bruce Schneier and Phil Zimmermann, the creator of email encryption package PGP - argue that any backdoor would be open to abuse by hackers, including foreign governments. Any such system would necessarily make software both more complex and harder to secure, as well as posing a privacy risk.
Advocates of updating CALEA say it should apply to encrypted VoIP channels, P2P and instant mobile messaging services to help fight organised crime and terrorism. The FBI argue the net is “going dark” to them, thanks to encryption technologies which render valid wiretapping warrants useless.
Computer scientists argue that the opposite is closer to the truth: information about people's movements and communications is more freely available than ever before, thanks to social networking and smartphones. Through moves such as the proposed "CALEA II" law, US agencies are getting closer to achieving their goal of real-time tapping of online communications. We are, therefore, living in a golden age of state surveillance.
In addition, critics point out that CALEA-mandated systems have been abused. For example, eavesdroppers tapped the mobile phones of the then Prime Minister of Greece, Kostas Karamanlis, his cabinet ministers and security officials for about nine months between June 2004 and March 2005 around the time of the Athens Olympics.
The spies used CALEA backdoors on Vodafone Greece switches to illegally plant spyware so that conversations were relayed to 14 “shadow” pay-as-you-go mobile phones.
The Greek newspaper Kathimerini on Sunday revealed in 2011 that four of those phones were originally purchased by the US embassy, although the eavesdroppers were never traced. In a similar case, AT&T's CALEA controls went through a Solaris machine that was rooted by hackers, giving crooks the ability to tap into calls.
Critics of CALEA also point out that if endpoint wiretaps were mandated in the US there would be nothing to stop software developers creating non-compliant software elsewhere, and then releasing it as open source code. There would be no way of preventing this technology from being imported into the US and rendering the whole proposal largely pointless - at least, when applied against criminals and terrorists.
In this scenario, the general population and corporate users would be using technology that is easier for hostile parties to wiretap, the crypto boffins warn (PDF, 7 pages).
The FBI’s desire to expand CALEA mandates amounts to developing for our adversaries capabilities that they may not have the competence, access, or resources to develop on their own. In that sense, the endpoint wiretap mandate of CALEA II may lower the already low barriers to successful cybersecurity attacks.
We believe that on balance mandating that endpoint software vendors build intercept functionality into their products will be much more costly to personal, economic and governmental security overall than the risks associated with not be ing able to wiretap all communications.
Weakening device security makes users more vulnerable to criminals and spies without really inconveniencing terrorists or fraudsters, even for those who trust US government agencies not to abuse increased wiretap powers.
Ed Felten, one of the computer scientists opposed to wiretapping endpoints - be they on smartphones or PCs - summarises the reservations of crypto-boffins in a blog post here.
"The plan would endanger the security of US users and the competitiveness of US companies, without making it much harder for criminals to evade wiretaps," Felten explains. ®