A difficult decision.

Posted on October 29, 2015. Filed under: Uncategorized | Tags: , , , , |

I’ve just decided not to renew my membership of a particular “professional” body. There are many reasons behind this, but the main one is that I’m tired of hearing that they “don’t understand digital”.

I really can’t say any more without ranting, so let’s leave it at that.

This decision may have a knock-on effect on the membership of various committee where I’ve been representing that organisation, in spite of (what I consider to be) a lack of support. We shall have to wait and see.

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ByeSO

Posted on April 20, 2015. Filed under: business, forensic, iso | Tags: , , , |

Last week I had to step down from my role as the UK’s Principal Expert on Digital Evidence to ISO/IEC JTC1 SC27 WG4 (to give it the full title – with incorrect punctuation before any reminds me).

It wasn’t something I particularly wanted to withdraw from, but the economics of it just didn’t make sense any more.

Since 2011 I’ve been attending editorial meetings, in various cities around the world, twice a year and also attended numerous meetings of BSI committees in London. The cost of doing this has come out of my business, with occasional (infrequent) small contributions from government agencies.

I’ve had to allocate at least 2 months a year to this, and it’s cost something in the region of £5k to £10k each year to support it.

It was a worthwhile activity. I’ve met and worked with some great people to develop some really useful standards, and I’ll miss them and that whole process – but the lack of support from the UK has just become unsustainable.

Unlike many of the participants, I’m from a micro-business. If I’m not doing or bringing in the work, the cash isn’t coming in either. So, I’ve had to take my accountant’s advice and stop donating to commercial bodies (the publishers and assessors make profits from the resulting standards) for standards development.

It’s a shame. Standards are genuinely useful things, especially for small businesses as they let us show that we are, at least, equivalent to the big boys. If only we could find a way to fund small businesses’ participation in standards development, instead of relying on the big multi-nationals to do it all for us.

Meanwhile, if you want to know the true intent behind ISO/IEC 27041 and 27042, please do get in touch – I was editor for them during most of the development time and I know what the words really mean (ISO English, as I may have mentioned before, is not what you think it is.)

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Bugs

Posted on June 8, 2012. Filed under: forensic | Tags: , , , , , , , , |

Well, it’s been an interesting couple of months since I last posted. We’ve been keeping busy with a couple of contracts from the Home Office. One is, of course, on digital evidence standards – but the other was a little bit different.

We were lucky enough to be awarded the contract to produce the entomology standard for the forensic science regulator. Since this isn’t part of our usual skillset, we did have to bring in a couple of the UK’s leading forensic entomologists to help with it. Fortunately, our network of contacts is big enough that we found them quickly enough and had the pleasure of working with both the Natural History Museum and Met. Police as a result.

Aside from technical content, the new standard isn’t that different to the others that the regulator already has in place. Most of the new material is designed to help interpret the “master” standard (ISO/IEC 17025) for applications relating to creepy-crawlies without specifying exactly how to do anything (this is a commonly misunderstood aspect of this whole regulatory system – the supplier and the customer are supposed to agree what will be done and how. In the whole, the regulators and assessors just want to see evidence that such an agreement has been reached and that things have been done that way).

Anyway, we delivered ahead of schedule and on budget. Something which some people seem to consider unusual for government contracts. But then, when you’re dealing with quality systems, can you afford not to hit the targets ?

For more information about standards development, regulation or uses of forensic science, please contact us via http://www.n-gate.net/

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Time to think

Posted on March 29, 2012. Filed under: forensic | Tags: , , , , , , |

I’ve just spent the day at the RSA running a workshop as part of a project I’m engaged on for a major client. The theme was, unsurprisingly, based around digital forensic standards, processes and scenarios.

Lots of good stuff came out of it and there’s been a huge amount of support, but the disappointing thing was the response from just one organisation. Asked to participate in the project by coming to a one-day workshop and letting me visit them to observe their methods, they responded  (paraphrased)  :  “No. Too disruptive, no time, we have too much of a backlog”.

It seems to me that if you spend all your time trying to use your current methods to reduce a backlog of work, and failing, perhaps a bit of disruption and time off might pay dividends in the longer term.

What are your thoughts ?

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Excellent news

Posted on November 29, 2011. Filed under: All, Education, forensic | Tags: , , , , , , , , , , , , |

Yet again, other activities have kept me away from this blog for far too long. Personally, I think that’s probably a good thing. A mix of casework and research commissions means I can afford to eat properly again (and those who know me will know how important it is that I maintain my physique – particularly in the current high winds).

The major projects that are keeping me busy are on a new website : Forensic Excellence where work on two of the three major elements of “forensic” quality systems is underway. The other bit of news is that I have an interview for funding of some work on the third element, and hope to be able to kick that work off towards the middle of next year.

Onwards and sideways!

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Nothing else of significance…

Posted on July 31, 2011. Filed under: forensic | Tags: , , , , , , , |

This week I was approached to quote for a defence case. Helpfully, the solicitor sent me a copy of the prosecution statement so I could prepare a realistic quote. Unfortunately, for the “other side”, I’ve spent most of the week working on a couple of proposals for new ISO standards – including something on content of reports for various purposes – so was particularly sensitive to languages issues.

As soon as I saw the source of the statement, I knew I was going to find a phrase that troubles me – and there it was, near the end “Nothing else of significance was found”.

The report details the material upon which the case is based, but gives little in the way of context or other material found. It builds the case for the prosecution solicitor nicely, but doesn’t allow anyone else to form an opinion about the significance of the material because it doesn’t actually give any detail of anything except the “significant” material as determined by the report’s writer.

It’s a format and form of words that I’ve seen several times over the years, and every time I see it, it sounds an alarm.

I’ve always been told that my responsibility as an “expert witness” is to the court (or whoever is going to make a final judgment based on all the reports submitted), and is to state the facts and my interpretation as best I can based on the information available to me. If I find evidence of guilt, I should state it, if I find evidence of innocence, I should state that. I also believe that I should try to make as much information as possible available so that a proper judgment can be made.

To this end, I don’t just list things of “significance” but I try to give an indication of the context in terms which a non-practitioner can understand.

For example, if an email relates directly to the case, I don’t just list that email. I give the total number of emails found and the number found which involve the same people in the “significant” one. If illegal images are found, I try to determine how they have been downloaded, whether they’ve been deliberately saved or just cached, and whether there’s a pattern of searching or browsing that relates to them.

I try never to build a case directly myself but I will, quite happily, poke holes in someone else’s case – especially if they are concealing, deliberately or accidentally, useful information behind statements like “nothing else of significance was found”.

In my book, saying something like that is almost tantamount to dissembling. A digital evidence examiner rarely has the full facts and circumstances of the case available. A prosecution examiner or first responder will have no idea of possible defences or excuses. Limiting the report to the most damning evidence doesn’t help anyone.

Well – it doesn’t help anyone except the “other side”. A good independent examiner will read that sort of report and realise that there’s a lot more work they could do, and SHOULD do, to determine if a proper rebuttal can be produced – and that means more time and bigger fees. I’m not a fan of the use of Bayesian ratios in reports because I know how few people really understand them, but I know why some forensic disciplines use them – they force the reporting scientist to think about the evidence and alternative explanations, resulting in a closer examination of “insignificant” material at times.

At a time when pressure is on to reduce spending on legal aid, perhaps it’s time someone looked more closely at standard reports coming from both sides to see if they are really fit for purpose ? The better those reports are, the less work needs to be done performing re-examination, re-analysis and re-interpretation.

n-gate ltd.

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Valid conclusions?

Posted on July 12, 2011. Filed under: forensic | Tags: , , , , , , , |

WARNING : Initial thoughts on a recent situation ahead – incomplete  – more to follow, eventually !

Recently, the Casey Anthony trial in the USA has been a source of discussion in many fora, but most recently a bit of a “spat” seems to be in danger of breaking out between the developers of two of the tools used to analyse the web history.

Leaving aside the case itself, let’s start by looking at what the two developers have to say about the issue that came up during cross-examination :

http://blog.digital-detective.co.uk/2011/07/digital-evidence-discrepancies-casey.html

http://www.cacheback.ca/news/news_release-20110711-1.asp

No preference is implied by the ordering of those links, by the way, it’s just the order in which I became aware of them. I don’t use either tool – I have my own methods for doing these things when necessary.

Two issues arise from these two posts, for me :

i) Both developers admit that there were possible problems with their tools which may have resulted in incorrect results and no-one was aware of this until the two tools were run side by side

ii) Neither tool seems to have been validated for the case in question. I’m sure they were verified (i.e checked for conformance to design/specification) but not convinced that they were tested against the requirements for the case.

Here comes the repetitive bit : as far as I’m concerned under the requirements of current and proposed ISO standards, neither tool could be considered reliable. There is no clear documentation about errors nor is there evidence that either has been subjected to a proper structured validation process. Dual-tooling is not validation. It merely compares two implementations of methods designed to solve the same problem as the developers understand things. At no point does anyone check that the results are correct, just how similar they are. Two implementations of the same wrong algorithm are more likely than not to come up with the same wrong results.

This is typical of the issues we will see more and more of in the digital forensics world – we depend too much on third-party tools which use algorithms developed through reverse engineering and have not been completely tested.

I’m not suggesting that every tool needs to be tested in every possible configuration on every possible evidence source -that’s plainly impossible – but we do need to get to a position where properly structured validation is carried out, and records which document that validation – including areas which have NOT been tested – are maintained and made available.

An examiner should always be free to use new methods, tools & processes, but should be personally responsible for choosing them and justifying their use. Information about usage limits & limitations on testing are vital and any competent examiner should be able to carry out additional validation where it is needed.

Let the flamng (of this post) begin…

 

P.S. – I’ve been doing a lot of work on models & systems for validation recently – they’re currently commercially confidential but if you’ld like to discuss the issues more please do contact me via n-gate.net

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ISO ISO baby – part 2

Posted on April 20, 2011. Filed under: forensic, security | Tags: , , , , , , , , , , , |

Well, I’m just about back on BST after spending last week in Singapore. In the words of Robin Williams – “IT’S HOT!” out there, and sticky, but the locals are very friendly, the food is excellent (Kopi & Kaya Toast highly recommended for breakfast).

Of course, I wasn’t just out there for a “jolly” (but thanks for dinner Microsoft – I promise to say nice things about you for a few hours at least), but was attending the latest meeting of ISO/IEC JTC1 SC27 working groups. This is the “Information Technology – Security Techniques” sub-committee responsible for the infamous 270xx family of standards.

My main responsibility was to assist with the ongoing task of editing the 27037 “Guidelines for the identification, collection, acquisition and preservation of digital evidence” document. It’s coming along nicely, but we still have considerable debate about whether this is a standard for law-enforcement, Infosec. or both.

My own view is that, because of the nature of the committee responsible, it needs to be an Infosec. document which can be useful for everyone – including law enforcement. This approach to it seems to be paying off as some of the resistance to it is falling away.

The problem with treating it as a document for law-enforcement is that any international standard in this area is bound to come into conflict with local law, local procedure etc. (you’ll see the truth of that when you read the final version and see how often we have had to include a reminder about local legislation  etc. overriding the guidance). Worse still is the possibility that an ISO document might try to tell judges how to deal with evidence & matters of law.

We can do no more than issue some helpful information and try to set a minimum standard which will allow anyone involved in investigating digital incidents to have confidence that any organisation, working to the same standard, will use methods which are compatible. In that respect, ISO/IEC 27037 looks like it’s going to work. Ideally, of course, everyone will adopt is as a minimum standard – and that can only be good news, because there will better understanding of the issues surrounding digital evidence handling and fewer situations where examiners, like me, have to turn down cases because of problems in the early stages.

I just hope we can achieve the same with the three new projects that we’re hoping to launch in October – “Investigation Principles & Process”, “Guidelines for Analysis & Interpretation of Digital Evidence”, and “Guidance on assuring suitability and adequacy of investigation methods”.  We (the UK group) are also hopeful that our proposal for some new work on “Incident Readiness” (particularly investigate readiness) will also be launched in October.

If you have any suggestions for what should be included in those standards, please do let me know. These things are just written by “the great and the good” (proof : they let me play!) but are the result of debate, discussion and consensus. More ideas  = better results.

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In the footsteps of Bob & Bing

Posted on April 7, 2011. Filed under: forensic, security | Tags: , , , , , , , , , |

Just 2 more days till I’m off to the ISO/IEC SC27 meeting in Singapore and I couldn’t resist the opportunity to use a clip from a relevant film;)

Anyway – some interesting new agenda items have appeared. Of these the most significant is new discussion slot on “Digital Forensic Processes”, suggesting there may be some new work items (aka drafting of new standards). It’s not clear where the request for this has appeared from or exactly what it relates to.

Given that I volunteered to be a rapporteur for study periods on “Digital Evidence Readiness & Analysis” and “Digital Evidence Validation & Verification” it seems a little redundant to me. We (the UK panel dealing with these) are proposing that readiness should be considered as part of Incident Management since it involves planning & auditing, Analysis should probably sit inside the existing draft 27037 document about evidence recovery, since it shares many common features and requirements, and that there should be a new standard for Validation & Verification.

With those in place, we think we cover all the critical phases of an investigation (and we are not going to say “forensic” because we now believe it is appropriate to broaden the standards so that every investigation is carried out to a high standard just in case it needs to go to court) – so I’m curious where the extra discussion has come from. Maybe the committee has realised just how much I like the sound of my own voice ?

 

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Twits in court

Posted on March 28, 2011. Filed under: forensic | Tags: , , , , , , , , , , |

Here’s an interesting one – a friend of mine was giving evidence in crown court today and has just sent a text message to say that a journalist mentioned their name on Twitter.

Not so surprising ? Their name will probably appear in the press reports in tomorrow’s paper anyway. Well, yes – except for one thing. The tweeting was happening in real time. As the witnesses were being cross-examined a journalist was relaying highlights directly from the courtroom.

Now – I can’t help but wonder what effect this could have on the testimony of a witness who has yet to be called and who is being kept away from the court in a witness room. Usual practice calls for witnesses to give their evidence without hearing anyone else’s to ensure that they have not been influenced by anything that has happened in the court (with the exception of “experts” who have been granted the privilege of sitting in court to advise counsel).

Mobile data networks and blogging sites, of course, can completely destroy this isolation – witnesses can be sitting in the witness room receiving selected detail of the evidence as it is presented, possibly very carefully filtered by someone who really wants to influence them.

In this case, I don’t think that’s what happened – it’s just yet another instance of someone using a technology without thinking through the consequences.

Perhaps it’s time to revisit the issue of technology in court – cameras have been banned almost since they were invented – perhaps we need a blanket ban on everything which can communicate with the outside world, in the interests of impartiality and fairness for all ? Perhaps news, just like travel and food, would be better for being a little slower ?

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    This is the weblog of Angus M. Marshall, forensic scientist, author of Digital Forensics : digital evidence in criminal investigations and MD at n-gate ltd.

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