Allicient

In the past few months, I have become increasingly aware of a glaring problem with the security model banks, utility companies, et al, use for their customer services. So a slightly irate and vitriolic post follows…

As online security gradually improves, the security of telephone based services has either stagnated or actually deteriorated. The old maxim of a chain being only a strong as it’s weakest link is sitting in eager anticipation of again being proven correct.

The problems can be split into some broad classifications:

i) the protection against replay attacks that (most) banks use for their online services are not used over the telephone;

ii) authentication credentials are often shared between strong online and weak phone services;

iii) static personal details are used as part of the authentication process over the telephone;

iv) there is an invalid assumption made that the phone call is private and secure;

v) telephone requests tend to “trump” anything done via online services;

vi) unsolicited calls are made from banks to customers that require only the customer to authenticate;

vii) catch phrases are overriding common sense.

The first problem highlighted above, (i), can be illustrated by example. Most banks request only a subset of a “PIN” or password when authenticating to an online banking service, however over the phone almost all banks ask for the full login credentials. For example, the Co-operative Bank has recently improved it’s online security immensely: logins only request a subset of details, there is a second stage of authentication whereby a random selection of one of four preset questions are asked, and most importantly before any transaction can be performed it must be authenticated via a smart card + card reader device. However, upon phoning, the automated service immediately asks for the full PIN. The problem is exacerbated by (iv), specifically that online services are at least encrypted using SSL/TLS, however phone calls are easily tapped if the attacker is physically in the local area.

The second problem, (ii), has some not-so-subtle ramifications. If a phone call to a bank’s customer services is monitored by an attacker, they will often have the credentials necessary to login online. From an anonymity point of view, it would be much more favourable for an attacker to action transactions using the online service as opposed to the telephone service.

The third problem, (iii), is that most telephone services use an automated system that verifies account number against “PIN” or password, then passes the call onto a real advisor. At this point, the advisor will attempt to further confirm the callers identity by asking the standard “name, address, postcode, date of birth” questions. Unfortunately, unless you are the Messiah, things like date of birth won’t change that often. So considering that these details are usually easy to come by and are exposed over an unsecure line anyway, it is worrying that so much trust is placed in them.

The fourth problem, (iv), is that most banks, government departments, etc assume that the telephone is a secure method of communication. It is not. Technologically, it is trivial to tap a person’s phone line. I have lost count of the amount of very personal details and information that I have had no choice but to submit over the phone.

The fifth problem, (v), is that once you’ve authenticated yourself to a bank or similar institution over the phone – they will usually action almost anything. So if an attacker has managed to garner your authentication credentials from previous phone calls, they will pretty much have carte-blanche.

Now onto (vi). This is probably the most concerning development. In the last six months I have had a bank, a utility company, and several other similar institutions phone me without my prior request, then ask me to authenticate myself to them. Each time I have illustrated that I do not know who they are, and they they could be a complete stranger calling to obtain my details. Out of the lot of them, the only one to both understand what I was saying and to be able to appropriately authenticate themselves to me first was Scottish Power.

The last one is more insidious than it first appears, (vii). When I challenged the customer services representatives over (vi), the response I got to every question was “but it’s Data Protection”. It was obvious that the person on the other end of the phone understood what I was saying but it seems company policy generally overrides the security beneficial attribute of common sense. So the public are now left trying to swallow a bunch of meaningless catch phrases like “data protection” and “passing security”: I wonder how many of the people writing the guidelines for these departments has ever read the contents of the Data Protection Act.

There are of course mitigating factors. The two that come to mind are using a 3G mobile which has half decent encryption as standard for (iv), and caller id for (vi). However these are not always available and are not addressing the core problems: namely that trust in the security of phone services are vastly over estimated.

Ah well, rant over.

UPDATED 12th April 2010: Added [] extra meaning in title; changed author.

While the issue of cybersquatting is generally very well documented, I think we’re just beginning to see the rise of a phenomena far more insidious and damaging – and it is likely to affect the average person-on-the-street much more than it does celebrity personalities or big business.  What I’m talking about is online identity theft, or maybe “profile theft”.  Most of the time when you hear the words “identity theft”, thoughts of horror stories start coming to mind, but have you considered your “online identity”?  By that, I mean social networking or “blogging” sites like Facebook, MySpace, Digg, and the likes – if you haven’t, then it may be something worth looking into.

In the days of olde, and by that I mean anything pre-dating circa 2000, most people didn’t have an online presence as such.  Email was really just beginning to be seen as something nifty, cool or vaguely useful (despite it being around since the ’70s).  When you wanted to contact someone, you’d use the phone, or you could send an SMS message on their funky new mobile phone, you could even write a note/letter.  At a pinch you could even go round to their place.  If you lost contact, you’d likely have to ask amongst your friends or family if they knew how to contact them.  Notice in all of these, you can easily establish someone’s identity – be it via face-to-face interactions, their voice on a phone, handwritting, etc – the act of communication itself carried enough information to identify that person as the person you think it is.

Now consider the situation we have today.  You want to find someone, you can use a multitude of online services from Facebook to Friends Reunited – that person may even have their own website.  You might be able to do a Google search and find online tracks left by them.  Unfortunately, there is little inate information carried online to actually identify a person unless you are directed to a specific URL or profile by someone you already trust.  So, what’s the problem; you can just make sure you’re a little more careful when you make contact with someone to make sure they are who you think they are.  But that belies the true natrue of the problem: other people may not use such stringent checks.

This might not seem a risk until you consider the scenario where someone else creates accounts and profiles in your name.  They may even take photos from your own legitimate profiles, or use publically available information about you to make it more convincing.  Somebody you knew years ago who is trying to look you up may inadvertantly make contact with the forgery (which if taken to an extreme could have some pretty serious consequences), or the impersonator may put up false information on the forged profile which is damaging to your reputation.

Preventing this is fairly difficult due to a number of factors:  there are a lot of sites where you can network or “locate” people, which means a massive work load if you wanted to check for impersonations; even if you manage to do this, then its difficult to get the forged profiles or accounts removed; it’s much easier and quicker for an impersonator to create new profiles or accounts, so you’re fighting a losing battle; any damage may already have been done – to use an old axiom, its like trying to lock the barn door after the horse has bolted.

The problem is basically down to the loss of authentication information that was present in the ways we used to do things.  You would recognise a person’s voice or handwritting, but that’s not there in an anonymous email or online profile.  Passing on of contact details also had a certain amount of inbuilt protection as there was an assumed trust in the person giving you the information and an ultimate authentication when you actually talked to the person you wanted to contact.  Ironically, a partial solution to this problem has been around since the early ’90s with the advent of a bit of software called PGP (Pretty Good Privacy), which was principally designed for secure email communication between people who didn’t have a secure channel to send passwords or encryption keys (the software’s designer, Phil Zimmerman ended up getting brought up on arms charges by the US government because of it, and is often praised for promoting free speech).  PGP brought with it the concept of a Web of Trust – which basically means that if you have met your good friend Bob in real life, then you can in the electronic world state that fact, in a very secure and unforgable sense.  Assuming both Bob and yourself have done this with your whole social circle, then if someone Bob knows wants to email someone you know but hasn’t yet met, they can email with some certainty that it is the correct person – and not have to meet in person or talk on the phone.  A simple situation where this would be useful is that one of Bob’s friend’s lives in the US but wants to do business with someone you know – timezones are difficult, so being able to email off-spec and know for certain its the correct person is a useful thing.

When I was in my early teens, I’d actually obtained one of the very first versions of PGP (through a 2.4Kbps modem dialup to a BBS… ahhh the days).  Immediately, I’d recognised the importance of the Web of Trust construction.  Unfortunately when you are still at school and all your friends live within a three mile radius, it has somewhat limited applicability.  I do however think this concept has yet to really manifest in the psyche of the general internet public, and when it does, we’ll approach our online relationships in a completely different manner.

Its all fine and well for me to talk about using webs of trust, but the problem exists now; so what can you realistically do?  Well, for starters create your own profiles on the major social networking sites.  You don’t have to use them, but having them established is a good start.  It means that if someone malicious creates a profile in your name then anyone looking for you will see a duplicate and alarm bells will be raised.  The second piece of advice would be to get at least a minimum number of people you talk to on a daily basis to be on your “friends list” – an impersonator will find this hard to do with people you talk to everyday and will increase the authenticity of your profile.  The third piece of advice actually flies in the face of the prevailing thoughts on identity protection: publish a physically verifiable contact detail; a mobile number would even suffice, just enough so that someone that wants to contact you can phone and actually determine its you.  If you’re worried about your personal details, “Pay-as-you-go” mobiles come in at little over £15 now, just use that as your online contact.

** Update, Tuesday 23rd September 2008: to see just how dangerous online impersonation can be, have a look at this article. This debarcle happening on Wikipedia no-less, who would have thought it. Ah-hem. The article here is also useful for background.

UPDATED 12th April 2010: Added [] extra meaning in title.