Watching Your Backdoor

It’s a thing. Backdoors. Add no, not the fun kind with screens that keep out mosquitoes. The kind I’m going to reference here are the ones that actually let worse things in.


Backdoors in tech aren’t just the stuff of legend, or part of the plot in tales of espionage. They are very real,  and there is nothing secure about them. They exist as an intrusion point, hidden, secret. These deliberate manipulations of code allow access into a network or application and bypass the necessary security protocols.  What matters to me isn’t so much that these are used by foreign governments to spy on us, or for corporate espionage. Rather, it’s the further legitimization of attacks on our privacy.  How do we secure against this mindset? Backdoors are essentially a weakness built into the code. Something unsecured that when discovered can be readily exploited, because nobody is supposed to know it’s there. Until it’s too late.

Several backdoors have recently been revealed just over the past few months.Here’s the rundown of shame by John E Dunn in his article in Forbes:

NSA Clipper Chip, 1993

The most reviled backdoor in history, the NSA’s infamous Clipper chip, endorsed by the Clinton administration, still gets people’s backs up more than two decades on from its heyday. In 1993, encryption was new and strange. Few used it but the experts and Government spooks could, however, imagine a world in which they might. Their answer was to neuter the possibility of unbreakable security with an escrow-based system based around the Clipper chip that would cache keys. Assuming anyone had agreed to use it the NSA would have had a ready means to decrypt any content.

As Whitfield Diffie, creator of the famous Diffie-Hellman key exchange protocol observed at the time, the problem with building in backdoors is that they are deliberate weaknesses. Should a third-party find them they become less a backdoor than an open one.

Borland InterBase backdoor, 2001

This weakness in the firm’s InterBase database was essentially a secret backdoor account that allowed anyone with knowledge of it access to data. Making the serious comic, the username and password in question were ‘politically’ and ‘correct’. At the time, the assessment was that while deliberate the hole was probably put there by one or a small number of programmers as a convenience. But we’ve included it because the fact that perhaps only one person knew about it doesn’t mitigate its seriousness for the seven years until it was discovered.

Huawei v the US, 2011

The huge Chinese equipment maker spent millions trying to reform its image after being accused of building backdoors into its telecoms equipment. In 2012 a US Congressional investigation concluded that the firm (and mobile vendor ZTE) should be banned from the world’s largest market over state surveillance worries. In the UK BT had been installing Huawei equipment since 2007 so it was all too late to do much about it beyond GCHQ setting up a special unit to monitor its systems in cooperation with the company itself.

Irony or all ironies, a Snowden leak then suggested that the NSA’s Tailored Access Operations (TAO) had set up an operation to spy on Huawei to work out how far any collusion went.

The modern (i.e. post-Aurora and Stuxnet era of backdoor scandal began here.

Cisco et al, 2013

Dragged out of Snowden’s famous cache by a German newspaper, this concerned unpublished security flaws in the networking equipment of a group of vendors, headed by Cisco but including Juniper, Samsung among others. These weren’t classic backdoors except in the sense that they allegedly offered a huge amount of surveillance control over the equipment. Very unusually, Cisco’s CSO John Stewart issued a statement denying any knowledge of the compromise.

“As we have stated prior, and communicated to Der Spiegel, we do not work with any government to weaken our products for exploitation, nor to implement any so-called security ‘back doors’ in our products,” he stated. The fact he was even having to say this was a sign of changed times.

More recently in 2015, a backdoor compromise called SYNful Knock was discovered on Cisco equipment. Described by security fir FireEye as a Cisco router implant, already it was clear that the simple idea of intelligence engineers building in massive holes from day one of a product’s life was probably out of date. Why build them in when juicy ones could be found later on?

Juniper, 2015

Discovered just before Christmas 2015, this looked like a biggie in Juniper’s NetScreen ScreenOS from the off. The company finally admitted to suspicious researchers that the Dual_EC_DRBG encryption random number generator contained a backdoor that would allow anyone with knowledge of it to eavesdrop on secure VPN connections. This flaw might or might not have been deliberately put there by the NSA, which was he source of the RNG, but it was exploited at some point, possibly by a third-party government. A backdoor in a backdoor or just weak coding?

Fortinet, 2016

Hard-coded passwords are an absolute no-go for any system these days so it was disconcerting to discover that Fortinet appeared to have one in an SSH interface accessing its FortiOS firewall platform. Researchers looked on this as a backdoor although Fortinet strenuously denied this interpretation. In fairness, this was probably correct although the lack of transparency still bothers some.


Was the revelation that this protocol, promoted by the UKs CESG for end-to-end encryption in VoIP phone calls, a real backdoor or simply part of the spec? According to Dr Steven Murdoch of University College London the escrow architecture used with MIKEY-SAKKE simply has not been fully explained. Was this a way to spy on conversations without anyone knowing? According to GCHQ, that’s exactly what it was. As an enterprise product, escrow was perfectly appropriate and organisations deploying this technology needed a system of oversight.

In fairness to MIKEY-SAKKE setting up end-to-end encryption without some form of backdoor is now unthinkable for large enterprises that need control over their encryption infrastructure. Whether this compromises the system in a wider sense seems over-blown assuming the architecture has been correctly documented.


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