That earth-shattering NSA crypto-cracking: Have spooks smashed RC4?

Ageing cipher at heart of HTTPS and VPNs fingered by experts

Finding the internet's skeleton keys

Another theory is that the NSA is exploiting a weakness in crypto key management. This might be a weakness in the way that keys are generated, or it could be a weakness in the way that the secret data is stored.

Dave Anderson, senior director at Voltage Security, commented: "It seems likely that any possible way that the NSA might have bypassed encryption was almost certainly due to a flaw in the key management processes that support the use of encryption, rather than through the cryptography itself. So, is it possible that the NSA can decrypt financial and shopping accounts? Perhaps, but only if the cryptography that was used to protect the sensitive transactions was improperly implemented through faulty, incomplete or invalid key management processes or simple human error."

Voltage markets encryption and key management technology but El Reg's security desk doesn't think that invalidates Anderson's expert perspective, even though there's a degree of self-interest in pointing towards a potential problem close to home. Other experts think the biz may be onto something in warning about possible shortcomings in the way encryption keys are generated.

"Most of the NSA claims could be explained by ability to crack 2048-bit RSA, or server certs generated weakly," said Marsh Ray, a security researcher and software developer at Microsoft-owned two-factor authentication service PhoneFactor.

The latest disclosures fail to detail which algorithms and products the spooks can snoop on. Previous revelations have revealed that the NSA routinely stores encrypted traffic transmitted over Tor for subsequent cryptanalysis.

'Weaken encryption and random number generators'

Matthew Green, a cryptographer and research professor at Johns Hopkins University, was quizzed by the ProPublica news website, which partnered with The Guardian and the New York Times in shedding fresh light on the NSA's anti-crypto operations.

His take on what the NSA might be doing is the most complete we've seen. According to Green, spooks are "working with hardware and software vendors to weaken encryption and random number generators", attacking the encryption used by "the next generation of 4G phones", and establishing a Human Intelligence division to infiltrate the global telecommunications industry.

Green singles out weakening the integrity of SSL as the gravest violation of privacy; the NSA reportedly blows $250m a year working on just that.

Meanwhile, Mikko Hypponen, chief research officer at F-Secure, points to leaked evidence [PDF] that the NSA makes cryptographic modifications to commercial security devices to "make them exploitable".

ISPs, DNS services, and bent certificate authorities (CAs) may all potentially be involved in one one or another, as well as software developers and infrastructure firms. Public Key Infrastructure (PKI) - a building block of modern cryptography - and the whole security model underpinning e-commerce and VPNs suddenly looks a whole lot less secure.

And if the NSA and GCHQ have these abilities then it's no great stretch to imagine their equivalent agents in Russia, China, France, Israel, and other nations, all have similar capabilities or are working towards the same goals.

The NSA-GCHQ's multi-front attack against encryption seems to involve manipulating crypto standards (perhaps including the NIST), stealing encryption keys and perhaps even planting backdoors. But all is not lost and what's needed is perhaps a different perspective on the problem of safeguarding privacy from government dragnet-style surveillance. This is not the cryptopocalypse.

"Strong crypto raises the costs - we must build alternatives to spying with economics as well as mathematics," writes Jacob Appelbaum, a leading Tor developer.

Bruce Schneier has written a guide on how to stay secure against NSA surveillance that's well worth reviewing here - regular Reg readers may already be familiar with them. ®