The Technology of PhreakingEdit

In the 1960s and 1970s, phone companies relied on a signaling protocol known as in-band signaling. This scheme sent data (i.e. the caller’s voice) and control signals over the same line[1]. Accordingly, should an individual understand and possess to capability to recreate these control signals, they would be able to manipulate the phone system from any user endpoint. This principle is the core foundation of phreaking: the use of tone generators to trick automated phone machines into performing executive operations.

The first manifestation of this principle was in the 2600 hertz tone, which was the control tone of single frequency systems[2]. On any single frequency system, producing a 2600 hertz tone in differing patterns allows one to give various commands to the phone system, including disconnecting a call, inputting numbers, and reconnecting.

A more popular and more complicated system was the multifrequency signaling system, which communicated information by sending pairs of pulses at different frequencies[3]. Although the 2600 hertz tone was still an important signal in this protocol, phreaking a multifrequency system is inherently more challenging. Many of these tones were published in Bell System Technical Journal’s “Signaling Systems for Control of Telephone Switching”[4].

A tool developed to aid in multifrequency phreaking was the blue box. These devices, the first of which was constructed by Washington State College student Ralph Barclay[5], produce the multifrequency tones necessary to phreak in a reliable reproducible way[6].

Rise in PopularityEdit

Budding InterestEdit

Joybubbles, born Josef Engressia, was one of the earliest phreakers. Born blind, Joybubbles had a perfect pitch, allowing him to replicate the precise tones made by the telephone. His curiosity helped him discover ways to maneuver and exploit the phone system. Joybubbles claims his phreaking interest is purely intellectual, saying “I’m not trying to beat the system when I accidentally get an overseas phone call free...I’m just trying to learn”[7]. Early phreakers shared this interest. Often making calls across the world, these pioneers were more concerned with what could be discovered next than trying to exploit the system.

John Draper was one of these pioneers. He earned the nickname Cap’n Crunch for discovering a whistle, found in Cap'n Crunch cereal boxes, that happened to produce the coveted 2600 hz tone used to make free calls. In a manner similar to Joybubbles, he states “I’m not out to screw Ma Bell. I know better. If I do anything it’s for the pure knowledge of the System. You can learn to do fantastic things”[8]. He was one of the most prominent and notorious members of the early phreaking community.

Public AdoptionEdit

In October of 1971, Esquire Magazine published the article “Secrets of the Little Blue Box,” an article discussing preaking and featuring John Draper[9]. Introducing phreaking to the masses, this article explained in detail the technology behind phreaking, the way a blue box worked, and how these devices could be used to exploit the phone companies. It also included interviews from many well known phreakers, including both Joybubbles and John Draper (known in the article only by his codename). It even coined the term "phreak"[10]. The article exposed the masses to phreaking for the first time, piquing the interest of both a new generation of phreakers and the agencies tasked with regulating them.

Among those captivated by the article included a young Steve Wozniak. Intrigued like many phreakers before him, Wozniak phoned Steve Jobs and excitedly explained what he had read. Together, they found a reference manual that listed telephone frequencies, very similar to the notorious "Signaling Systems for Control of Telephone Switching". After failing to build a blue box from analog tone generators, due to their lack of precision, Wozniak built his own digital blue box, saying “I have never designed a circuit I was more proud of”[11]. The duo would go on to meet John Draper during their days at Berkeley to review blue box designs, and eventually manufactured and sold their blue boxes to their peers. Their activities would be investigated by the FBI, but the boxes were never tied back to them[12].

Establishment ResponseEdit


The spread in popularity of phreaking was problematic for Bell System. It cut into their profits, exposed their system to those with nefarious intent, and was incredibly poor publicity. In 1977, AT&T issued an internal memo for their public relations staff, stating that “toll fraud imposes a big financial burden on the telephone industry and honest customers[13]”. To combat this phenomenon, AT&T sought to increase their capability to detect phone tampering. From 1972-1976, 823 blue boxes were seized and 411 toll fraud convictions occurred[14]. In 1973, Bell contrived a method to detect potential blue box use. When toll free calls were made without showing up on telephone company records, a device could be connected to the line showing if a blue box was being used[15]. This method led the arrest of prominent phreaker Sanford Herschel Kosman[16].

Regulatory Agency ResponseEdit

The FBI, as the regulatory agency primarily responsible for the enforcement of federal law, took a keen interest in the activities of phreakers. Especially prompted on by the Esquire article, they sought to discourage use of phreaking techniques and especially the manufacturing and selling of phreaking tools. Additionally, they gave special attention to those most prominent in the phreaking community.

Joybubble’s unique knowledge and abilities made him the subject of many magazine and newspaper articles. This spotlight, however, also exposed him to federal attention. In 1969, the FBI finished an investigation involving “espionage; interception of communication”[17] by Joseph Engressia. In the report, Engressia and a partner admitted to being able to intercept toll calls on Autovon, a highly classified telephone system used by the White House. Joybubbles was not arrested until June of 1971 for “possession of electronic equipment to bypass lawful charges for long distance telephone service.-- Obtained phone service by fraud”[18]. He was fined $10.

More than a year after Joybubble’s arrest, Draper was arrested for “fraud by wire”[19]. He was arrested again in 1976 for toll fraud[20]. In 1978, he was jailed for possession of a red box and other items used to steal communication services.[21].


Many factors contributed to the eventual decline of phreaking. The technological fall began in 1976, when Bell System began to convert from in line signaling to Common Channel Interoffice Signaling (CCIS). This new system allowed long distance calls to be completed faster and more reliably. However, critically, CCIS “handles key pieces of information about an attempted call on circuits separate from those used for talking”[22]. Therefore, any phone system using CCIS is impervious to traditional phreaking.

These issues were further compounded in 1984 by the Bell System breakup. Under US Antitrust law, Bell System was broken up into 8 constituent companies[23]. This breakup accelerated the change in Bell protocols and infrastructure that had been occurring.

Continued ImportanceEdit

Though no longer practiced, parallels can be drawn between phreaking and more modern practices such as hacking. The most obvious line of descendence is through phreaking’s role in facilitating early hacking techniques, most famously wardialing.

This connection can clearly be seen in the infamous zine Phrack, which covered phreaking and hacking, sometimes in the same edition. It would lead to be a major cultural force for hackers, publishing seminal articles such as Hacker’s Manifesto[24] and Smashing the Stack for Fun and Profit[25].

More than just being technologically related, though, the two phenomena have a similar social structure as well. As seen in Hacker’s Manifesto[24], many early hackers were defined by a strong sense of curiosity towards these new technological systems, similar to the curious group of phreakers previously noted. This pattern is also seen by Dorothy Denning in her own article in Phrak, where she describes hackers as “playing with systems and making them do what they were never intended to do.”[26]. These kinds of hackers now tend to be categorized as white or grey hat hackers.

Of course, not all are satisfied to hack only as an intellectual exercise. Many black hat hackers exist, and execute attacks such as the WannaCry ransomware attack, hacking systems to exploit them for money or other personal power. These participants align closely with those who used phreaking for personal gain.

As with phreaking, these exploits don’t occur in isolation -- they occur on servers, networks, and infrastructures owned and operated by individuals in corporations, who align closely with the telephone networks of the phreaking era.

These companies continue to be protected by government agencies, who continue to persecute those who exploit systems against their wishes. One such case is that of Anthony Swartz, who in 2010 downloaded nearly 80% of the documents on JSTOR using an unauthorized access point on the MIT network[27]. Swartz subsequently faced heavy charges from the United States Attorney’s Office under the Computer Fraud and Abuse Act. In 2013, he would commit suicide. His family released a statement describing Swartz’s death as “the product of a criminal justice system rife with intimidation and prosecutorial overreach”[28] -- a sentiment which has only grown in recent years.

In these ways the social dynamics of modern hacking align closely with those of phreaking, and as the groups are motivated largely by powerful feelings such as curiosity and self-preservation, it seems likely that whatever culture arises from hacking in the coming decades may also follow a similar set of dynamics and groups as well.


  1. Petersen, J.K. (2002). The Telecommunications Illustrated Dictionary. CRC Press. p. 467. ISBN 0-8493-1173-X. 
  2. Weaver and Newell (1954), In-Band Single-Frequency Signaling, The Bell System Technical Journal: AT&T, p. 1309, http://explodingthephone.com/docs/db447 
  3. Dahlbom, Horton, and Moody (1949), Application of Multifrequency Pulsing in Switching, 68, AIEE Transactions: AT&T, p. 392, http://explodingthephone.com/docs/db446 
  4. Dahlbom and Breen (1960), Signaling Systems for Control of Telephone Switching, 39, The Bell System Technical Journal: AT&T, p. 1381, http://explodingthephone.com/docs/dbx0445.pdf 
  5. FBI (1961), FBI File 165-HQ-25, Redacted Subjects, Fraud By Wire, FBI via FOIA: FBI, http://explodingthephone.com/docs/dbx0947.pdf 
  6. Rosenbaum, Ron (1971), Secrets of the Little Blue Box, Esquire Magazine: Esquire Magazine, p. 116, http://explodingthephone.com/docs/dbx0092.pdf 
  7. Glass (1970), I like to Whistle Up my Friends Long-distance, http://explodingthephone.com/docs/dbx0393.pdf 
  8. Rosenbaum, Ron (1971), Secrets of the Little Blue Box, Esquire Magazine: Esquire Magazine, p. 121, http://explodingthephone.com/docs/dbx0092.pdf 
  9. Rosenbaum, Ron (1971), Secrets of the Little Blue Box, Esquire Magazine: Esquire Magazine, p. 120, http://explodingthephone.com/docs/dbx0092.pdf 
  10. Lapsley, Phil (2013). Exploding the Phone: The Untold Story of the Teenagers and Outlaws who Hacked Ma Bell. Grove Press. p. 174. ISBN 978-o-8021-9375-9. 
  11. Lapsley (2013), The Definitive Story of Steve Wozniak, Steve Jobs, and Phone Phreaking, The Atlantic, p. 1, https://www.theatlantic.com/technology/archive/2013/02/the-definitive-story-of-steve-wozniak-steve-jobs-and-phone-phreaking/273331/ 
  12. Collection of FBI File Excerpts Discussing Blue Boxes with Notes Saying "He's Got the Whole World in His Hands", The United States Government, 1975, p. 1-2, http://explodingthephone.com/docs/db1030 
  13. AT&T Memo/Backgrounder on Toll Fraud, AT&T, 1977, p. 1, http://explodingthephone.com/docs/db570 
  14. AT&T Memo/Backgrounder on Toll Fraud, AT&T, 1977, p. 3, http://explodingthephone.com/docs/db570 
  15. Hager (1973), Electronic Sleuth Sniffs Out Illegal Free Phone Calls, The Bell System Technical Journal: Los Angeles Times, p. 22, http://explodingthephone.com/docs/dbx0040.pdf 
  16. Hager (1973), Electronic Sleuth Sniffs Out Illegal Free Phone Calls, The Bell System Technical Journal: Los Angeles Times, p. 22, http://explodingthephone.com/docs/dbx0040.pdf 
  17. [http://explodingthephone.com/docs/dbx0878.pdf FBI File 139-HQ-3481, Joseph Carl Engressia and two redacted subjects, Security Matter-espionage; Interception of Communications], FBI, 1969, p. 1, http://explodingthephone.com/docs/dbx0878.pdf 
  18. Arrest Record of Josef Carl Engressia, Jr., Shelby Count Sheriff's Office, 1971, p. 1, http://explodingthephone.com/docs/dbx0927.pdf 
  19. [http://explodingthephone.com/docs/dbx1029.pdf United States v. John Thomas Draper, United States District Court for the Northern District of California, No. CR-72-973 RFP (SJ), Judgment], United States District Court for the Northern District of California, 1954, p. 1, http://explodingthephone.com/docs/dbx1029.pdf 
  20. Phone Phreak Indicted Again, Oakland Tribune, 1976, p. F13, http://explodingthephone.com/docs/dbx0971.pdf 
  21. Joseph (1978), 'Phone Phreak' jailed for 3 to 6 months, The Pocono Record, p. 17, http://explodingthephone.com/docs/dbx0071.pdf 
  22. McElheny, Victor K (1976), New Phone Setup to Save Time and Circuits, New York Times: New York Times, http://explodingthephone.com/docs/db1033 
  23. Pollack, Andrew (1984), BELL SYSTEM BREAKUP OPENS ERA OF GREAT EXPECTATIONS AND GREAT CONCERN, New York Times: New York Times, p. 12, https://www.nytimes.com/1984/01/01/us/bell-system-breakup-opens-era-of-great-expectations-and-great-concern.html 
  24. a b The Mentor (1986), "The Conscience of a Hacker", Phrak 1 (7), http://www.phrack.org/issues/7/3.html 
  25. aleph1 (1996), "Smashing the Stack for Fun and Profit", Phrak 7 (49), http://www.phrack.org/issues/49/14.html 
  26. Denning, Dorothy (1990), "Concerning Hackers Who Break into Computer Systems", Phrak 3 (32), http://www.phrack.org/issues/32/3.html 
  27. JSTOR Evidence in United States vs. Aaron Swartz, JSTOR, 2013, https://docs.jstor.org/ 
  28. Swartz, Robert; Swartz, Susan; Stinebrickner-Kauffman, Taren (2013), Official statement from family and partner of Aaron Swartz, http://www.rememberaaronsw.com/statements/family.html