Clearswift Ltd v Glasswall (IP) Ltd
| Jurisdiction | England & Wales |
| Judge | David Stone |
| Judgment Date | 28 September 2018 |
| Neutral Citation | [2018] EWHC 2442 (Pat) |
| Court | Chancery Division (Patents Court) |
| Docket Number | Claim No: HP-2017-000019 |
| Date | 28 September 2018 |
[2018] EWHC 2442 (Pat)
IN THE HIGH COURT OF JUSTICE
BUSINESS AND PROPERTY COURT
OF ENGLAND AND WALES
INTELLECTUAL PROPERTY LIST (ChD)
PATENTS COURT
Royal Courts of Justice
Rolls Building
Fetter Lane, London, EC4A 1NL
David Stone
(sitting as a Deputy Judge of the Chancery Division)
Claim No: HP-2017-000019
Dr. Brian Nicholson and Mr. Christopher Hall (instructed by CMS Cameron McKenna Nabarro Olswang LLP) for the Claimant
Mr. Richard Davis and Mr. Sam Carter (instructed by Harbottle & Lewis LLP) for the Defendant
Trial dates: 10, 11, 12, 16 and 17 July 2018
Judgment Approved
David Stone (sitting as a Deputy Judge of the Chancery Division):
These proceedings concern the validity of a single patent owned by the defendant, Glasswall (IP) Limited (“Glasswall”). The relevant patent is the United Kingdom designation of European Patent EP 1 891 571 B1 titled “resisting the spread of unwanted code and data” (the “Patent”). The Patent was applied for by an entity called Avecho claiming a priority date of 9 June 2005, and assigned to Glasswall prior to its grant in 2013.
The validity of the patent is challenged by the claimant, Clearswift Limited (“Clearswift”), an anti-malware provider, only on the basis of lack of inventive step over two items of prior art:
(a) United States patent application 2005/0081057A1 entitled “Method and system for preventing exploiting an email message” (“Cohen”) published on 14 April 2005; and
(b) A series of posts on an Internet bulletin board under the subject line “Avecho Glasswall Anti virus technolog? [sic]” (“Avecho”) published in full by 23 December 2003.
Clearswift seeks the revocation of the Patent under section 72(1)(a) of the Patents Act 1977 (the “Patents Act”) for lack of an inventive step (sections 1(1)(b) and 3 of the Patents Act).
Although Glasswall initially asserted the independent validity of claims 2, 3 and 4 of the Patent, this assertion received very little attention during the trial and was dropped during closing speeches. There was no application to amend the Patent. There was also no counterclaim for infringement. Therefore, the only issue before the Court was the validity of claim 1 of the Patent over the two items of prior art.
Clearswift's counsel described claim 1 of the Patent as embodying “quite a simple concept”. He also described this case in his closing submission as “relatively routine”. Despite this, and the apparently narrow issue on invalidity, a significant amount of material was presented to the Court. Clearswift filed three reports from its expert (on the first day of the trial, I gave permission to adduce the last of these reports for reasons I set out at the time) totalling 628 paragraphs. Glasswall's two reports from its expert totalled 313 paragraphs. There were nearly 10 hours of cross-examination. In addition, I was presented with 27 technical papers totalling 528 pages (only 3 of which I was taken to during the trial) and a 711 page text book from 2005, The Art of Computer Virus Research and Defense by Peter Szor (“Szor”). In addition, there were a further 40 exhibits, only one of which I was taken to during the trial. Clearswift's skeleton arguments in opening and closing totalled 380 paragraphs, and Glasswall's 285 paragraphs. I have taken all of this material into account, but I have not referred to all of it in this judgment, because it is not necessary to do so. It was probably not necessary for much of it to be before the Court, particularly as this case was governed by the costs budgeting regime, limiting the recovery of costs.
From time to time, Clearswift's submissions appeared to suggest that the Patent was obvious over the common general knowledge. For example, in his opening submissions, Clearswift's counsel wrote “the Patent presents nothing more than a particular non-inventive, application of the well-established [common general knowledge] techniques”. This was repeated in closing. This was not however, Clearswift's pleaded case, as expressly averred by Clearswift's counsel. I have therefore only assessed obviousness in relation to the two pleaded pieces of prior art.
I was made aware of unrelated proceedings between the parties in the United States involving different patents – I was asked to have no regard to those proceedings, and I have adopted that course.
Dr Brian Nicholson and Mr Christopher Hall appeared for Clearswift. Mr Richard Davis and Mr Sam Carter appeared for Glasswall.
Outline
Malware including computer viruses has been the scourge of computer users for many years. The rapid increase in Internet use (and particularly email use) in the 1990s led to an increase in the proliferation of malware, and a concomitant proliferation of anti-malware software to try to prevent it.
In 2005, the majority of anti-malware software worked by scanning for malware, or evidence of the presence of malware. Incoming files (including emails) were scanned, and blocked (or parts of them blocked) if evidence of malware was detected. Scanning systems could only look for what they knew – so new malware could not be detected until the anti-malware software had been updated. This was, in essence, a form of blacklisting – that is, known malware was included on the blacklist so that it could be stopped. The drawback was that malware could not be included on the blacklist until it had been detected, and the software updated.
Some anti-malware software also used whitelists – for example, allowing through files (or parts of files) including emails where the file type or the sender was recognised, and included on a safe list.
The Patent claims to take “an entirely different approach to protection against unwanted code”. Rather than looking for known “bad” code, Glasswall says that the Patent teaches “parsing” and “regeneration” of each file – in effect, breaking it down, extracting its content and rebuilding it according to known rules – so that only “good” code is passed on to the recipient. Any “bad” code is left behind, but the regeneration occurs regardless of whether any malware is identified. The Patent also teaches a threat filter which allows through files which could not be parsed and/or regenerated if the sender and file type appeared on a whitelist.
Clearswift points to Cohen, a US patent published some 7 weeks prior to the Patent, and Avecho, a bulletin board exchange in which various experts discussed the Glasswall anti-malware software that was available at that time. Clearswift posits a different construction for the Patent, but says on any construction, there was no inventive step from Cohen and/or Avecho to the Patent. Clearswift says that Cohen and the Patent are doing the same thing in the same way. In relation to Avecho, Clearswift says that Avecho discloses to the skilled person the whole of the relevant claim of the Patent.
I am conscious that no brief outline can do justice to the detailed arguments advanced by the parties – the above is provided at the start of this judgment to provide context.
The witnesses
There were no witnesses of fact. Each party called a single expert witness.
Alexander Shipp
Alexander Lawrence Shipp is an experienced anti-malware practitioner. He is currently the Chief Technology Officer of Equine Register Limited, but in his earlier career, he developed expertise in designing and evaluating anti-malware technology. Mr Shipp studied computer science at Cambridge University and graduated in 1983. He worked in industry in a number of roles relating to computing before joining MessageLabs. MessageLabs offered a variety of anti-malware solutions. Mr Shipp was responsible for the team which developed MessageLabs' anti-malware capabilities. He had the title Imagineer – he was responsible for imagining things. He was a pioneer in the field of malware detection in real time. Mr Shipp also regularly visited and presented computer security briefings at organisations including GCHQ, NATO, the FBI and national Computer Emergency Response Teams in various countries. A list of Mr Shipp's ten patents was provided to the Court.
Mr Shipp was clearly a very knowledgeable witness. He was able to give well-considered evidence as to the common general knowledge of the skilled person, including as at the relevant time. His evidence was criticised in two ways by Glasswall. These were said by Glasswall's counsel not to render Mr Shipp's evidence unreliable, but to “colour it”. It was suggested that I needed occasionally to take care with Mr Shipp's evidence.
First, it was said that Mr Shipp could not reliably distinguish between what was known, and what was common general knowledge. It was also said that he could not reliably distinguish between what could be done and what was obvious to do. I accept this criticism to a limited degree. In my judgment, Mr Shipp well appreciated that he was not himself the skilled person for the purposes of the legislative test, and he did his best to ensure that his evidence was given from the correct perspective. I do not accept that he was “imagineering” in his evidence – a reference to his earlier job title put to him in cross-examination. However, as would be expected of an expert witness, he clearly knew more in 2005 (and knows more now) than the common general knowledge, and some care must be taken with his evidence in this regard.
The second criticism of Mr Shipp was that “he was there to argue his case”. I accept this criticism to a very small degree.
These are, however, minor and understandable issues. Overall, I found him to be a witness who expressed himself clearly and was of significant assistance to the Court.
Professor Christopher Mitchell
Professor Christopher Mitchell is Professor of Computer Security at Royal Holloway,...
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