6 Interesting Facts About SIGINT


In military practice, law enforcement, and intelligence agencies, signals intelligence (SIGINT) is crucial. It provides information that may not be provided for by other branches of intelligence gathering such as human intelligence (HUMINT) or measurement and signature intelligence (MASINT).

SIGINT is a method of gathering intelligence through signal interception. Encrypted data is translated through cryptoanalysis to decipher the real message.

Does this concept sound too alien? How much do you know about SIGINT?

Here are some interesting facts about SIGINT that are nice to know:

1. SIGINT dates back to the 1900s.

The first practice of SIGINT was believed to occur during the Boer War that started in 1899. The British belligerents placed wireless devices on board their Royal Navy ships.

Upon the Boers’ seizure of the wireless devices, they used these to establish transmissions, too. Since only the British used these at that time, that signals were not encrypted, and hence did not need decryption.

Later on, SIGINT practice continued during the Russian-Japanese War from 1904-1905. The British naval ship, that time positioned in the Suez Canal, intercepted transmissions from the Russian vessels as they were preparing for battle with Japan.

When British forces utilized SIGINT in intercepting German radio signals, the use of cryptography then gained prominence. Because of its effectiveness in concealing the content of radio transmissions, cryptoanalysis is still being widely practiced today.

Since then, SIGINT methods developed intricately to provide vital military and tactical intelligence.

2. Intercepting radio waves is legal.

When the radio was invented in 1895, it revolutionized how people communicated with one another. Generally, no one can own radio waves. Privacy laws don’t cover these, either. Interception is legal in this case, in contrast to wiretapping.

SIGINT is a broad term that consists of two fields: COMINT (communication intelligence) and ELINT (electronic intelligence).

COMINT includes telephone calls, text messages, and online chats. It aims to obtain information such as the identity and location of the communicators, the length and time of the communication, and the encryption used.

ELINT focuses on the more technical aspect of the communication itself, such as electric signals. It aims to assess the radar capability of the target by using special sensors. Since this is commonly used in military practice, data obtained through ELINT is usually classified.

3. The Snowden Effect revealed the extent of SIGINT use by the US.

In 2013, Edward Snowden leaked a series of documents from the National Security Agency (NSA). A former contractor of NSA, he disclosed the extent of the agency’s surveillance methods. The Snowden effect forced the NSA, regarded as a very secretive agency, to explain itself to the public.

The growing public concern over US surveillance activities, hailed as the “Snowden effect”, affected the cloud-buying practices by companies.

In 2015, the NSA once more came into the limelight when Laura Poitras produced the film CitizenFour based on Edward Snowden.

In the same year, the United States Court of Appeals ruled that the NSA’s phone surveillance activities were illegal.

4. SIGINT applies to electronic warfare.

Electronic warfare (EW) utilizes non-hostile methods to enter the electromagnetic spectrum while denying the enemy’s access to the same.

One of EW’s sub-disciplines, Electronic Warfare Support or ES, focuses on the identification of electromagnetic energy sources.

For instance, ES analysts detect an unidentified radar signal and consequently determine the type. They compare it to countries who utilize this specific type of radar, including the aircraft, vessels, and vehicles used with it. Ultimately, they can identify the nature and source of the radar.

The practice of SIGINT overlaps ES in this case, as it supports decision-making for military intelligence.

5. SIGINT has ethical implications.

Any information transmitted electronically constitutes SIGINT. This includes sources from the Internet, telephone lines and radio transmissions, whether intercepted or sent to the wrong destination.

SIGINT does not touch on publicly accessible information, such as text messages or e-mails addressed to you.

However, deliberately gaining access to your opponent’s server, using programs to intercept messages, or hacking e-mail accounts are downright unethical.

How about information that’s mistakenly sent to you? Have you received a text message that wasn’t addressed to you? This is a more subtle, practical context of SIGINT when compared to its use in full-scale military operations.

However, receiving a message not intended for you happens every once in a while. Due diligence must be practiced. If you do receive a message by mistake, the ethical action is to advise the sender of the mistake, inform the appropriate department, and ignore or delete the information before it falls to the wrong hands and deliberately passed on.

6. SIGINT aids in decision-making for policy-makers.

We know that certain agencies like the NSA gather raw SIGINT for the translators and cryptologists to transform it into information that an analyst can scrutinize.

Once the raw SIGINT is processed and analyzed, the information is passed to other intelligence agencies such as the CIA. They collate information gathered from other sources to generate complete intelligence. This is vital for policy-makers that focus on pertinent issues like nation-building and national security.

Based on this process, we can say that producing finished intelligence is a tedious and meticulous task.

Because of the technological advancements of this age, intelligence collectors are overwhelmed with the high volume of signals. This makes it even more arduous for analysts to gather, sort, track, and extract the important data from the irrelevant ones.