Getting started in IT security – an in/outsider’s view

… a basic grounding in cryptography is vital …

I am, by many measures, almost uniquely badly qualified* to talk about IT security, given that my degree is in English Literature and Theology (I did two years of each, finishing with the latter), and the only other formal university qualification I have is an MBA.  Neither of these seem to be great starting points for a career in IT security.  Along the way, admittedly, I did pick up a CISSP qualification and took an excellent SANS course on Linux and UNIX security, but that’s pretty much it.  I should also point out in my defence that I was always pretty much a geek at school***, learning Pascal and Assembly to optimise my Mandelbrot set generator**** and spending countless hours trying to create simple stickman animations.

The rest of it was learnt on the job, at seminars, meetings, from colleagues or from books.  What prompted me to write this particular post was a post over at IT Security guru, 9 out of 10 IT Security Pros Surveyed Favour Experience over Qualifications – FireMon, a brief analysis of a survey disclosed on Firemon’s site.

This cheered me, I have to say, given my background, but it also occurred to me that I sometimes get asked what advice I have for people who are interested in getting involved in IT Security.  I’m wary providing a one-size-fits-all answer, but there’s one action, and three books, that I tend to suggest, so I thought I’d share them here, in case they’re useful to anyone.

An action:

  • get involved in an Open Source project, preferably related to security.  Honestly, this is partly because I’m passionate about Open Source, but also because it’s something that I know I and others look for on an CV*****.  You don’t even need to be writing code, necessarily: there’s a huge need for documentation, testing, UI design, evangelism****** and the rest, but it’s great exposure, and can give you a great taster of what’s going on.  You can even choose a non-security project, but considering getting involved in security-related work for that project.

Three books******* to give you a taste of the field, and a broad grounding:

  1. Security Engineering: A Guide to Building Dependable Distributed Systems, by Ross Anderson. I learned more about security systems from this book than any other. I think it gives a very good overview of the field from a point of view that makes sense to me.  There’s deep technical detail in here, but you don’t need to understand all of it on first reading in order to get a lot of benefit.
  2. Practical Cryptography, by Bruce Schneier. Schneier has been in the field of security for a long time (many of his books are worth reading, as is his monthly email, CRYPTO-GRAM), and this book is a follow-up to his classic “Applied Cryptography”. In Practical Cryptography, he admitted that security was more than just mathematics, and that the human element is also important. This book goes into quite a lot of technical depth, but again, you don’t have to follow all of it to benefit.
  3. Cryptonomicon, by Neal Stephenson. This is a (very long!) work of fiction, but it has a lot of security background and history in it, and also gives a good view into the mindset of how many security people think – or used to think!  I love it, and re-read it every few years.

I’m aware that the second and third are unashamedly crypto-related (though there’s a lot more general security in Cryptonomicon than the title suggests), and I make no apology for that.  I think that a basic grounding in cryptography is vital for anyone wishing to make a serious career in IT Security.  You don’t need to understand the mathematics, but you do need to understand, if not how to use crypto correctly, then at least the impact of using it incorrectly********.

So, that’s my lot.  If anyone has other suggestions, feel free to post them in comments.  I have some thoughts on some more advanced books around architecture which I may share at some point, but I wanted to keep it pretty simple for now.


*we could almost stop the sentence here**, to be honest.

**or maybe the entire article.

***by which I mean “before university”.  When Americans ask Brits “are you at school?”, we get upset if we’ve already started university (do we really look that young?).

****the Pascal didn’t help, because BBC BASIC was so fast already, and floating point was so difficult in Assembly that I frankly gave up.

*****”Curriculum Vitae”.  If you’re from North America, think “Resumé”, but it’s Latin, not French.

******I know quite a lot about evangelism, given my degree in Theology, but that’s a story for another time.

*******All of these should be available from a decent library.  If your university/college/town/city library doesn’t have these, I’d lobby for them.  You should also be able to find them online.  Please consume them legally: authors deserve to be paid for their work.

********Spoiler: it’s bad.  Very bad.

Disbelieving the many eyes hypothesis

There is a view that because Open Source Software is subject to review by many eyes, all the bugs will be ironed out of it. This is a myth.

Writing code is hard.  Writing secure code is harder: much harder.  And before you get there, you need to think about design and architecture.  When you’re writing code to implement security functionality, it’s often based on architectures and designs which have been pored over and examined in detail.  They may even reflect standards which have gone through worldwide review processes and are generally considered perfect and unbreakable*.

However good those designs and architectures are, though, there’s something about putting things into actual software that’s, well, special.  With the exception of software proven to be mathematically correct**, being able to write software which accurately implements the functionality you’re trying to realise is somewhere between a science and an art.  This is no surprise to anyone who’s actually written any software, tried to debug software or divine software’s correctness by stepping through it.  It’s not the key point of this post either, however.

Nobody*** actually believes that the software that comes out of this process is going to be perfect, but everybody agrees that software should be made as close to perfect and bug-free as possible.  It is for this reason that code review is a core principle of software development.  And luckily – in my view, at least – much of the code that we use these days in our day-to-day lives is Open Source, which means that anybody can look at it, and it’s available for tens or hundreds of thousands of eyes to review.

And herein lies the problem.  There is a view that because Open Source Software is subject to review by many eyes, all the bugs will be ironed out of it.  This is a myth.  A dangerous myth.  The problems with this view are at least twofold.  The first is the “if you build it, they will come” fallacy.  I remember when there was a list of all the websites in the world, and if you added your website to that list, people would visit it****.  In the same way, the number of Open Source projects was (maybe) once so small that there was a good chance that people might look at and review your code.  Those days are past – long past.  Second, for many areas of security functionality – crypto primitives implementation is a good example – the number of suitably qualified eyes is low.

Don’t think that I am in any way suggesting that the problem is any lesser in proprietary code: quite the opposite.  Not only are the designs and architectures in proprietary software often hidden from review, but you have fewer eyes available to look at the code, and the dangers of hierarchical pressure and groupthink are dramatically increased.  “Proprietary code is more secure” is less myth, more fake news.  I completely understand why companies like to keep their security software secret – and I’m afraid that the “it’s to protect our intellectual property” line is too often a platitude they tell themselves, when really, it’s just unsafe to release it.  So for me, it’s Open Source all the way when we’re looking at security software.

So, what can we do?  Well, companies and other organisations that care about security functionality can – and have, I believe a responsibility to – expend resources on checking and reviewing the code that implements that functionality.  That is part of what Red Hat, the organisation for whom I work, is committed to doing.  Alongside that, we, the Open Source community, can – and are – finding ways to support critical projects and improve the amount of review that goes into that code*****.  And we should encourage academic organisations to train students in the black art of security software writing and review, not to mention highlighting the importance of Open Source Software.

We can do better – and we are doing better.  Because what we need to realise is that the reason the “many eyes hypothesis” is a myth is not that many eyes won’t improve code – they will – but that we don’t have enough expert eyes looking.  Yet.


* Yeah, really: “perfect and unbreakable”.  Let’s just pretend that’s true for the purposes of this discussion.

** …and which still relies on the design and architecture actually to do what you want – or think you want – of course, so good luck.

*** nobody who’s actually written more than about 5 lines of code (or more than 6 characters of Perl)

**** I added one.  They came.  It was like some sort of magic.

***** see, for instance, the Linux Foundation‘s Core Infrastructure Initiative

Changing the demographic in IT security: a radical proposal

If we rule out a change in age demographic, gender, race or ethnicity, what options do we have left?

This is a guest post by Sherlock.

We have known for a while now that we as an industry don’t have enough security specialists to manage the tide of malware and attacks that threaten to overwhelm not just the IT sector but also all those other areas where software and hardware security play a vital part in our way of life.  This is everything from the food supply chain to the exercise industry, from pharmaceuticals to wildlife management.  The security sphere is currently dominated by men – and the majority of them are white men.  There is a significant – and welcome – move towards encouraging women into STEM subjects, and improving the chances for those from other ethnic groups, but I believe that we need to go further: much, much further.

There is also an argument that the age demographic of workers is much too skewed towards the older range of the employment market, and there is clear evidence to show that humans’ mental acuity tends to decrease with age.  This, in a field where the ability to think quickly and react to threats is a key success metric.  The obvious place to start would be by recruiting a younger workforce, but this faces problems.  Labour laws in most countries restrict the age at which significant work can be done by children*, so one alternative is to take the next age demographic: millennials.  Here, however, we run into the ongoing debate about whether this group is lazy and entitled***.  If we rule out a change in age demographic, gender, race or ethnicity, what options do we have left?

It seems to me that the obvious solution is to re- or up-skill a part of the existing security workforce and bring them into the IT security market.  This group is intelligent*****, loyal******, fast-moving [I’m done with the asterisks – you get the picture], quick-thinking [see earlier parenthetical comment], and easily rewarded [this bit really is universally true].  In short, the canine workforce is currently under-represented except in the physical security space, but there seems to be excellent opportunity to up-skill a large part of this demographic and bring them into positions of responsibility within the IT security space.  So, next time you’re looking to recruit into a key IT security role, look no further than your faithful hound.  Who’s a good boy?  Who’s a good boy?  You‘re a good boy.


*this is a Good Thing[tm] – nobody**’s complaining about this

**apart from some annoying kids, and well, who cares?

***I could have spent more time researching this: am I being ignorant or apathetic?****

****I don’t know, and I don’t care.

*****mostly

******again, mostly

The Backdoor Fallacy: explaining it slowly for governments

… I literally don’t know a single person with modicum of technical understanding who thinks this is a good idea …

I should probably avoid this one, because a) everyone will be writing about it; and b) it makes me really, really cross; but I just can’t*.  I’m also going to restate the standard disclaimer that the opinions expressed here are mine, and may not represent those of my employer, Red Hat, Inc. (although I hope that they do).

Amber Rudd, UK Home Secretary, has embraced what I’m going to call the Backdoor Fallacy.  This is basically a security-by-obscurity belief that it’s necessary for encryption providers to provide the police and security services with a “hidden” method by which they can read all encrypted communications**.  The Home Secretary’s espousal of this popular position is a predictable reaction to the terrorist attack in London last week, but it won’t help.  I literally don’t know a single person with modicum of technical understanding who thinks this is a good idea.  Or remotely practicable.  Obviously, therefore, I’m not the only person who’s going to writing about this, but I thought it would be an interesting exercise to collect some of the reasons that this is monumentally bad idea in one short article, so let’s examine this fallacy from a few angles.

  • It always fails – because a backdoor isn’t just a backdoor for authorised users: it’s a backdoor for anyone who can find it.  And keeping these sort of things hidden is difficult, because:
    • academic researchers look for them
    • criminals look for them
    • “unfriendly state actors” (governments we don’t like at the moment) look for them
    • previously friendly state actors (governments we used to like, but we don’t like so much anymore) look for them
    • police and security services mess up and leak them by accident
    • insiders within police and security services decide to leak them
    • source code gets leaked, giving clues to how they’re implemented -for those apps which aren’t Open Source in the first place
    • the people writing them don’t always get it right, and you end up with more holes than you expected***
    • techniques that seem safe now often seem laughably insecure in a few years’ time.

There is just no safe way to protect these backdoors.

  • You can’t identify all the providers – today it’s Whatsapp.  And Facebook, and Twitter, and Instagram, and Tumblr, and …  But if I’d asked you for a list a year, or five years ago, what would that list have looked like?  And can you tell me what should be on the list for next week, or next year?  No, you can’t.  And I suspect you (as a learned reader of this blog) are a lot more clued up than the UK Home Office.
  • You can’t convince all the providers – and that’s assuming that all of the providers are interested or can be convinced to care adequately to sign up anyway.
  • You can’t hit all channels – even if you could identify all the providers, what about online gaming?  And email.  And ssh.  I mean, really.
  • The obviousness issue – presumably, in order to make this work, governments need to publish a list of approved applications.  I suspect, just suspect that the sort of bad people who want to get around this will choose to use different apps, or different channels to the approved ones … but so will people who aren’t “bad people”, but just have legitimate reasons for encrypting their communications.
  • The business problem – there are legitimate uses for encryption.  Many, many of them.  And they far outnumber the illegitimate uses.  So, if you’re a government, you have two options:
    1. you can convince all legitimate business, including banks, foreign corporations and human rights organisations and everyone who communicates with them to use your compromised, “backdoor-enhanced”***** encryption scheme.  Good luck with this: it’s not going to work.
    2. you can institute a simple, fast, unabuseable red-tape free process by which you hand out exemptions to “legitimate” businesses who you can trust to use non-compromised, backdoor-unenhanced encryption schemes.******

I’m guessing that we don’t expect either of these to fly.

  • The “nothing to hide” sub-fallacy – “But if you have nothing to hide, then you have nothing to fear” argument.  Well, I may have nothing to hide from the current government.  But what about future governments?  Have the past 100 years of world history taught us nothing?  Hitler, Franco, Stalin, Perón, … the list goes on and on.  From “previously friendly state actors”?  And from the criminals who are the main reason most of us use encryption in the first place?  Puh-lease.
  • The who-do-you-trust question – this leads on from the “police and security services mess up” sub-bullet above.  The fewer people to whom you give the backdoor details, the more hard work and expense there is in using that backdoor for your purposes.  So there’s an obvious move to reduce costs by spreading knowledge of the backdoor.  And governments tend towards any policy which reduces costs, so…  And, of course, the more spread the knowledge, the more likely it is it leak.
  • Once it’s gone, it’s gone – and once it’s leaked, it’s leaked, whether by accident or intention (Chelsea Manning, Julian Assange, Edward Snowden, …).  You can’t put this genie back in the bottle.  The cost and complication of re-keying a communications channel for which the key has leaked is phenomenal.  I’m assuming that this is just a re-keying exercise, but if it’s a recoding exercise, it’s even harder.  And how do you enforce that only the new version is used, anyway?
  • The jurisdiction issue – do all governments agree on the same key?  No?  Well, then I have to have different versions of all apps I might use, and choose the correct one for each country I travel in?  And ensure that neither I nor any businesses ever communicate across jurisdictional boundaries.  Or we could have multiple backdoors, each for a different jurisdiction?  Let’s introduce the phrase “combinatorial explosion” here, shall we?

Let’s work as an industry to disabuse governments of the idea that this is ever a good idea. And we also need to work them to come up with other techniques to help them catch criminals and stop terrorist attacks: let’s do that, too.


*believe me: I tried.  Not that hard, but I tried.

**they probably want all “at-rest” keys as well as all transport keys.  This is even more stupid.

***don’t get me wrong: this is going to happen anyway, but why add to the problem?

****inverted commas for irony, which I hope is obvious by this state in the proceedings

*****”I can’t even”, to borrow from popular parlance.  This is the UK government, after all.

Ignorance as a virtue: being proud to say “I don’t know”

“I am the wisest man alive, for I know one thing, and that is that I know nothing.” Socrates

In order to be considered an expert in any field, you have to spend a lot of time learning things.  In fact, I’d argue that one of the distinguishing traits of someone who is – or could become – an expert is their willingness and enthusiasm to learn, and keep learning.  The ability to communicate that knowledge is another of those traits: you can’t really be an expert if you have no way to communicate that knowledge.  Though that doesn’t mean that you need to be a great speaker, or even a great writer: by “communicate” I’m thinking of something much broader.  In the field of security and IT, that communication may be by architecture diagram, by code writing, by firewall rule instantiation, or by GUI, database or kernel module design, to name just a few examples.  These are all ways by which expertise can be communicated, instantiated or realised: the key is that the knowledge that has been gained is not contained, but can be externalised.

There’s another trait that, for me, betrays a true expert, and that’s the ability to say “I don’t know”.  And it’s difficult.  We enjoy and cultivate our expert status and other’s recognition of it: it’s part of our career progression, and it hits the “esteem” block in Maslow’s Hierarchy of Needs[1].  We like people asking our opinion, and we like being able to enlighten them: we take pride in our expertise, and why wouldn’t we?  We’ve earned it, after all, with all that hard graft and studying.  What’s more, we’ve all seen what happens when people get asked a question to which they don’t know the answer to something – they can become flustered, embarrassed, and they can be labelled stupid.*  Why would we want that for ourselves?

The problem, and very particularly in the security field, is that you’ll always get found out if you fake it.  In my experience, you’ll go into a customer meeting, for instance, and there’s either the sandal-wearing grey-beard, the recently-graduated genius or just the subject matter expert who’s been there for fifteen years and knows this specific topic better than … well, possibly anybody else on the planet, but certainly better than you.  They may not be there in the first meeting, but you can bet your bottom dollar*** that they’ll be in the second meeting, or the third – and you’ll get busted.  And when that happens, everything else you’ve said is called into question.  That may not seem fair, but that’s the way it goes.  Your credibility is dented, possibly irreparably.

The alternative to faking it is to accept that awkward question and simply to say, “I don’t know”.  You may want to give the question a moment’s thought – there have been times when I’ve plunged into an response and then stopped myself to admit that I just can’t give a full or knowledgeable answer, and when I could have saved myself bother by just pausing and considering it for a few seconds.  And you may want to follow up that initial acknowledgement of ignorance by saying that you know somebody else who does (if that happens to be true), or “I can find out” (if you think you can) or even “do you have any experts who might be able to help with that?”

This may not impress people who think you should know, but they’re generally either asking because they don’t (in which case they need a real answer) or because they’re trying to trip you up (in which case you don’t want to oblige them).  But it will impress those who are experts, because they know that nobody knows everything, and it’s much better to have that level of self-awareness than to dig yourself an enormous hole from which it’s difficult to recover.  But they’ll also understand, from your follow-up, that you want to find out: you want to learn.  And that is how one expert recognises another.


* it’s always annoyed me when people mock Donald Rumsfeld for pointing out that there are “unknown unknowns”: it’s probably one of the wisest soundbites in recent history**, for my money.

** and for an equivalently wise soundbite in ancient history, how about “I am the wisest man alive, for I know one thing, and that is that I know nothing”, by Socrates
*** other currencies and systems of exchange are available

Systems security – why it matters

… to understand how things will work together, you have to consider them as a system…

“A system is a set of interacting or interdependent component parts forming a complex or intricate whole.  Every system is delineated by its spatial and temporal boundaries, surrounded and influenced by its environment, described by its structure and purpose and expressed in its functioning.” (Wikipedia: system)

I’ve been involved with various types of security over the years, from features within products to storage, network and other communications security, and including stand-alone application security, cryptographic protocol design and other weird and wonderful issues like why you shouldn’t lose too much weight on holiday.*  That’s a subject for another post.  But what I keep coming back to is systems security.

And that’s because you can design all the security into a particular component that you like, you take as much care in coding it as you like, you can ensure that you compile is safely, you can test it to within an inch of its life, and ensure that it is deployed where and how you like – but if it’s part of a system, and that system has other holes, than you might as well not bother.  We** often talk about “the weakest link in the chain” as a way of pointing out that if you have a single problem in a set of components, that’s what will break.  That’s too simplistic an analogy***, though, as different components interact in different ways with each other, dependent on a variety of factors.

In order to understand how things will work together, you have to consider them as a system, to define what their behaviour as a system will be, and to architect the system with an understanding of the risks, threats and likely attackers that it will have to deal with in its lifetime.

Much of the content this blog may discuss components, but I hope that I’ll manage to explain their place in systems, and how they work together.  Join me: I should be fun****.


*that’s a subject for another post – it’ll be fun

**by which I mean the nebulous “security community”

***don’t start me on analogies

****another disclaimer – I think that security is fun.  Not everybody agrees.  I’m presuming that the fact that you’ve made it this far means that you are at least open to the suggestion.