A history of British SIGINT (#1); the origins, 1850-1918

From the Second Boer War to the First World War

TL;DR

This newsletter is the first in a series covering the history of British signals intelligence (SIGINT). It looks at how SIGINT emerged, its initial development during the Second Boer War and the success it had during WWI.

Here are the key takeaways:

• SIGINT may have significantly matured during WWI, but it did not begin at that point. SIGINT was a practice starting to develop during the 1850s, and was first put to the test during the Second Boer War between 1899 and 1902.

• SIGINT operations during the Boer War were not that advanced. However, it provided a glimpse into the value of such intelligence, and this combined with the growth of radio encouraged Britain to grow its SIGINT capabilities.

• By the time WWI came around in 1914, Britain was well-positioned to deploy its SIGINT operations. The advantages it gave the British during the conflict was fairly consistent, and saw its intelligence community grow very quickly.

• The most important contribution British SIGINT made to WWI was the interception and decoding of the infamous Zimmermann telegram. This act, which revealed German plans to engage in submarine warfare in the North Atlantic and its proposal to Mexico for a military alliance, would bring the US into the war and help secure an Allied victory.

• WWI proved crucial for the development of British SIGINT in numerous ways. This includes the utilisation of cable networks and the private sector, the establishment of MI5 and MI6, the advancements in both interception and codebreaking, and the importance of capturing codebooks to enable the deciphering of encrypted messages.

What is SIGINT?

Simply put, signals intelligence (SIGINT) is the practice of extracting information from intercepted communications.

A more sophisticated definition is provided in s.3(1)(a) of the Intelligence Services Act 1994, which spells out the function of the Government Communications Headquarters (GCHQ) as the agency responsible for British SIGINT. That provision states that the function of GCHQ is to:

...to monitor, make use of or interfere with electromagnetic, acoustic and other emissions and any equipment producing such emissions and to obtain and provide information derived from or related to such emissions or equipment and from encrypted material...

Today, much of SIGINT is obtained via cyberspace. Because of this, almost everyone with access to the internet could be subject to SIGINT operations by GCHQ and other intelligence agencies around the world. The proliferation of the internet and the communications it conveys has led to a perception of mass surveillance, whereby the state is able to tap into and collect any communications or information that it wants, whenever it wants, however it wants and from whoever and wherever without limitations or constraints. The prospect of such mass surveillance received particularly widespread attention in 2013 after the Snowden revelations.

Why write about the history of SIGINT?

The Snowden revelations are what got me interested in the data rights space. It highlighted the importance of the happenings in the intersection between technology, the law and society. In other words, it highlighted to me how technological development has a significant impact on our wider society, and it is important to understand the risks that arise from this and how we deal with those risks to ensure a healthy and well-functioning society.

However, I felt that the Snowden revelations put a lot of focus on the regulation of SIGINT and how our security and intelligence agencies (SIAs) carry this out. And rightfully so of course - the revelations exposed the unlawful intelligence operations of the US and UK SIAs, in particular the NSA and GCHQ respectively, which eventually led to an improved legal framework (though it is far from perfect).

But an aspect of the debate that I think was missing was the importance of SIGINT and why it even exists in the first place. This does make sense in way, since the SIAs enjoy a great deal of secrecy and exclusivity regarding their work. Cf. from What even is national security?:

There are two key elements to the veil of national security:

1. Secrecy

2. Exclusivity

The first key element is about national security matters being protected from public eyes and therefore barred from public discussion. Such secrecy applies to information about national security threats, the methods used to combat them, and anything else that is relevant to these operations.

Secrecy is maintained by the 'neither confirm nor deny' (NCND) policy. This is a principle that the government will not confirm nor deny the accuracy of information related to national security matters if doing so would damage national security.

When invoked, the government will not respond to questions, claims or allegations about its national security work. This policy has been used in Parliamentary debate and in court proceedings.

The second key element is about matters of national security being solely reserved for the government and its agencies. This means that it is not for the courts or the legislature to decide which threats to prioritise and how they should be addressed.

Exclusivity is maintained by the separation of powers. This is a long-standing public law principle that the institutions of the state (the executive, the legislature and the judiciary) should be functionally independent.

This means that none of these institutions should be able to exercise the powers of the other. Only the executive can execute national security policy, only the legislature can pass national security laws, and only the judiciary can provide legal judgments on national security law and policy.

The rationale for secrecy and exclusivity is the operational efficacy of national security. Both elements contribute to this efficacy in different ways.

Secrecy prevents adversaries from learning about the measures used against them by the state and adapting their behaviour accordingly. Exclusivity ensures that national security decisions are made by agencies with the relevant information, resources and expertise.

These ideas were explored in the Zamora Case in 1916. This case concerned whether an order could be made by the government to requisition a neutral ship carrying contraband (copper) during wartime.

It was determined that such an order was illegal. But even in making this judgement, the House of Lords made reference the veil of national security.

On secrecy, it was asserted that matters of national security should not be “made the subject of evidence in a Court of law or otherwise discussed in public.” On exclusivity, it was asserted that “those responsible for the national security must be the sole judges of what the national security requires.”

Justifications have therefore been made for the veil of national security. It ultimately provides agencies like GCHQ and MI5 the opportunity to do their job effectively.

But another consequence of the veil is that it makes it more difficult to determine what national security actually is. It can distort what constitutes a national security threat and how they should be addressed.

This in turn complicates the scrutiny and accountability of government agencies responsible for executing national security operations. It is hard to critique the work of these agencies when their internal workings are largely inaccessible.

This has driven me to better understand the work of the SIAs, and in particular the work of GCHQ as the agency responsible for British SIGINT. I have always thought that a better understanding of this would provide a sound foundation to develop appropriate legislation covering such activity. By looking at the historical evolution of British SIGINT in particular, we can see how the capabilities of SIGINT have changed over time and the associated policy implications this has had.

Accordingly, this series aims to explore that historical evolution, starting with this post which covers the beginnings of British SIGINT in the 1850s and its eventual maturation during WWI. I will do so with the help of several books on the subject, including but not limited to:

• Richard J. Aldrich and Rory Cormac, The Black Door: Spies, Secret Intelligence and British Ministers (William Collins 2016)

• Paul F Scott, The National Security Constitution (Hart Publishing 2018)

• John Ferris, Behind the Enigma: The Authorised History of GCHQ, Britain’s Secret Cyber-Intelligence Agency (Bloomsbury 2020)

• David Khan, Seizing the Enigma: The Race to Break the German U-Boat Codes, 1939-1943 (Frontline Books 2023)