Fax Machines

Fax Machines

  1. From a whistleblower privacy point of view, Facsimile Machines (fax) combine the worst tracking features of land line telephones with the wear and tear induced characteristic blemishes of photocopiers and printers

  2. Most models of Fax machine display or print at the bottom of each page or at least at the end of each transmission, a customisable message line which identifies the name of the company or organisation sending the fax, with its fax telephone number. If you are publishing scanned images of faxed documents, you should pay attention to the redaction or censorship of this line .

  3. Since the words and numbers are user programmable (i.e. easily faked), you should not jump to immediate conclusions as to the authenticity of a faxed document, simply on the basis of this return address / return fax data

  4. Since long distance phone calls , which can often be common with Faxes, cost money, there are built in electronic memory and / or printed log files available of the recent Fax transmissions ad receipts, with the identifying phone numbers and times and dates. This should be borne in mind if you do use a shared fax machine to send any whistleblowing documents to journalists or bloggers.

  5. If you are sending sensitive material via fax, there is a small, but finite risk of mis-dialling, and sending it off to the wrong number entirely, which may betray a whistleblower.

  6. Sometimes, a supposedly mis-dialled fax number, has in the past, been used as the "plausibly deniable" cover story, to make a deliberate leak look accidental or to add credibility to a deliberately misleading fake leak.

  7. It is common practice to print or scribble a Fax Cover sheet with addressing information (and often with pre-printed Return Fax data on it. This can give clues as to authenticity of seemingly accidental fax leaks.

  8. Many fax machines nowadays are effectively digital scanners (sometimes combined with photocopy and printer devices), or they eschew the process of scanning paper and simply convert , say Word document computer files into Facsimile format and then transmit them.
    Such sophisticated Fax devices may very well keep copies of the original document data files or of the image scans in their internal memory or on their hard disks, in case the fax needs to be re-transmitted.

    Fax gateways will also keep a log file of time and date when the copy was made, and details of the computer which send the fax, and, if there is some sort of electronic payment or internal accounting system, the department or people or the individual corporate client account (very common in large legal firms, for example) to which the fax costs are to be allocated..

    Even when these files are apparently deleted or overwritten, they may not have entirely disappeared, and might well be recoverable through standard computer forensic techniques. Yet another reason for whistleblowers to be extremely careful when using fax machines.

  9. As with all heavily used office printing equipment, slight defects in manufacture, and heavy use, can induce characteristic blemishes on the output of a fax machine, which may provide sufficient clues to forensic investigators working for a major whistleblower leak inquiry, to track down the fax machine which was used to send whistleblowing revelations to a journalist or blogger etc.

    Consider digitally cleaning up any scratches, or other blemishes on image scans of faxed documents, before publishing them.

  10. There are some positive points about Fax machine telephone lines in offices, from a whistleblower's point of view, as these can very often have special privileges compared with the other phones in the building e.g.

    • they may be made available 24 hours a day, 365 days a year, when the other phones are disabled at night or at weekends and they can usually be used to make voice calls as well as to send faxes.

    • they may also be allowed to make international calls, when the normal office phones require permission from the switchboard operator.

    • they may be the only analog POTS phone lines left working in an otherwise VoIP office, and they could be used by a laptop computer user to dial out to another office or to for a dial-up Internet Connection, in order to send an email, which does not pass through the normal office internet gateway and its logfiles.

About this blog

We know that there are decent, honest, trustworthy individual politicians, civil servants, law enforcement, intelligence agency personnel and broadcast, print and internet journalists etc., who often feel powerless or trapped in the system. They need the assistance of external, detailed, informed, public scrutiny to help them to resist deliberate or unthinking policies, which erode our freedoms and liberties.

Some of these people will, in the public interest, act as whistleblowers, and may try to leak documents or information to the mainstream media, or to political blog websites etc.

Here are some Spy Blog "Hints and Tips", giving some basic preecautions, and some more obscure technical tips, which both whistleblowers, journalists, and bloggers need to be aware of, in order to help preserve the anonymity of whisteleblowing or other journalistic sources, especially in the United Kingdom, but applicable in other countries as well.

Whistleblower anonymity may not always be possible, or even necessary, forever into the future, but it is usuially crucial during at least the early stages of a "leak", whilst it is being evaluated by others, to see if it merits wider publication and publicity.

Email & PGP Contact

Please feel free to email your views about this blog, or news about the issues it tries to comment on.


Our PGP public encryption key is available for those correspondents who wish to send us news or information in confidence, and also for those of you who value your privacy, even if you have got nothing to hide.

You can download a free copy of the PGP encryption software from www.pgpi.org
(available for most of the common computer operating systems, and also in various Open Source versions like GPG).

We look forward to the day when UK Government Legislation, Press Releases and Emails etc. are Digitally Signed so that we can be assured that they are not fakes. Trusting that the digitally signed content makes any sense, is another matter entirely.


Tag Cloud

CryptoParty London

CryptoParty London

Most months there is a CryptoParty London event. where some of these Hints and Tips and other techniques are demonstrated and taught.

Usually at:

Juju's Bar and Stage 15 Hanbury St, E1 6QR, London

Follow on Twitter: @CryptoPartyLDN

Syndicate this site (XML):


Campaign Button Links

Watching Them, Watching Us, UK Public CCTV Surveillance Regulation Campaign
UK Public CCTV Surveillance Regulation Campaign

NO2ID Campaign - cross party opposition to the NuLabour Compulsory Biometric ID Card
NO2ID Campaign - cross party opposition to the NuLabour Compulsory Biometric ID Card and National Identity Register centralised database.

Gary McKinnon is facing extradition to the USA under the controversial Extradition Act 2003, without any prima facie evidence or charges brought against him in a UK court. Try him here in the UK, under UK law.
Gary McKinnon is facing extradition to the USA under the controversial Extradition Act 2003, without any prima facie evidence or charges brought against him in a UK court. Try him here in the UK, under UK law.

FreeFarid.com- - Kafkaesque extradition of Farid Hilali under the European Arrest Warrant to Spain

Peaceful resistance to the curtailment of our rights to Free Assembly and Free Speech in the SOCPA Designated Area around Parliament Square and beyond

Parliament Protest blog - resistance to the Designated Area restricting peaceful demonstrations or lobbying in the vicinity of Parliament.

Petition to the European Commission and European Parliament against their vague Data Retention plans
Data Retention is No Solution Petition to the European Commission and European Parliament against their vague Data Retention plans.

Open Rights Group

renew for freedom - renew your passport in 2006
Renew For Freedom - renew your Passport in the Summer Autumn of 2006.

The Big Opt Out Campaign - opt out of having your NHS Care Record medical records and personal details stored insecurely on a massive national centralised database.

Tor - the onion routing network
Tor - the onion routing network - "Tor aims to defend against traffic analysis, a form of network surveillance that threatens personal anonymity and privacy, confidential business activities and relationships, and state security. Communications are bounced around a distributed network of servers called onion routers, protecting you from websites that build profiles of your interests, local eavesdroppers that read your data or learn what sites you visit, and even the onion routers themselves."

Tor - the onion routing network
Anonymous Blogging with Wordpress and Tor - useful Guide published by Global Voices Advocacy with step by step software configuration screenshots (updated March 10th 2009).

Amnesty International's irrepressible.info campaign

BlogSafer - wiki with multilingual guides to anonymous blogging

NGO in a box - Security Edition privacy and security software tools

Home Office Watch blog, "a single repository of all the shambolic errors and mistakes made by the British Home Office compiled from Parliamentary Questions, news reports, and tip-offs by the Liberal Democrat Home Affairs team."

Reporters Without Borders - Reporters Sans Frontières - campaign for journalists 'and bloggers' freedom in repressive countries and war zones.

Committee to Protect Bloggers - "devoted to the protection of bloggers worldwide with a focus on highlighting the plight of bloggers threatened and imprisoned by their government."

Wikileaks.org - the controversial "uncensorable, anonymous whistleblowing" website based currently in Sweden.

Public Concern at Work - "(PCaW) is the independent authority on public interest whistleblowing. Established as a charity in 1993 following a series of scandals and disasters, PCaW has played a leading role in putting whistleblowing on the governance agenda and in developing legislation in the UK and abroad. All our work is informed by the free advice we offer to people with whistleblowing dilemmas and the professional support we provide to enlightened organisations."