Phone Phreakers

No acrobatics necessary -- find your toy whistle instead!

Phreaking is a slang term — now a common part of technology nomenclature — which is used to describe the activity of a subculture of people who study, experiment with, or explore (and yes, exploit) telecommunications equipment and public telephone networks. With the computerization of telephone networks, Phone Phreaking has become inseparably linked with computer hacking — often referred to as H/P Culture, or (hacking/phreaking).

While the ultimate goal in phreaking eventually turned out to be — let’s just say it —  toll fraud, by way of “tripping” or “tricking” a telephony network into providing free long-distance and international calls or to tap phone lines, it should be noted that the early phone phreaks were motivated by learning about the telephone network and how it operated.  In his Phone Phreak blog, Phil Lapsley admits that phone phreaks pointed out to him: “We didn’t have anyone to call”.  Lapsley further explains: “Think about it: if you’re a typical teenage kid in the late 1950’s or early 1960’s, it;s not like you have a far-flung network of long-distance buddies to call.” While free calling is a tangible “payoff”, it becomes evident — the more research one does into the topic — that the mere “sport” of Phreaking; the actual execution of new and intriguing ways of manipulating a system — and the acclaim and notoriety which goes along with it — is actual, calculable reward in and of itself.

While the exact origins of phone phreaking are a little hazy, it is believed that phreak-like experimentation began with the widespread deployment of automatic switches on telephone networks — namely with AT & T, which began introducing automatic switches for long distance and some trunking carriers in the mid-to-late 1950’s.  The automatic switches used tone dialing, a form of in-band signaling, and included some tones which were strictly and exclusively for internal telephone company use. When it was understood — among the growing community of those wishing to hack into public telephone networks — that the frequency for internal use was precisely 2600 Hz, automatic switches became vulnerable and ripe for attack.

That discovery — of that perfect frequency — came about accidentally in 1957 by a blind seven year old boy named Joe Engressia, who was blessed with perfect pitch, and who discovered, quite by chance, that by whistling the fourth E above middle C (a frequency of 2600 Hz), he could stop a dialed phone recording. (It bears noting that — apparently — a large percentage of early phone phreaks were blind or at least, sight-impaired — although with the cloaked nature of their identities, the actual number is unknown.) Engressia — unaware of what he had done — called the phone company and asked why the recordings had stopped. Unable to furnish him with an answer, the phone company likely didn’t give his query much thought — until phreaking picked up momentum.

A man code-named “Bill from New York” discovered that a recorder he owned could also play the 2600 Hz tone with the same effect, and an early phreaker named John Draper (whom I had the surreal experience of sitting next to at lunch during an Astricon convention) discovered through his friendship with Engressia that the free whistles given out in Cap’n Crunch cereal boxes  also, coincidentally, emitted the 2600 Hz tone (earning him his now-legendary nickname “Captain Crunch”). The replication — or matching — of the 2600 Hz tone allowed control of SF (single frequency) phone systems, and it was further discovered that a long whistle would reset the line; followed by groups of whistles (a short tone for “1”, two for a “2” and so on.) Different specially-designed boxes — named different colors (and yet not necessarily painted those colors) were intended for various different phreak approaches: a “black box” would enable free calls made from any home phone, a “red box” for making free calls on any payphone, and the infamous “blue box” provided complete control of the telephone system.

That was single frequency. The most common signaling on long distance networks became multi-frequency controls. What those specific frequencies were, was unknown until 1964, until Bell Systems themselves, in essence, gave away the “keys to the kingdom” by publishing the information in a Bell Systems Technical Journal, describing the methods and frequencies used for inter-office signalling. The journal was intended for the company’s engineers; it soon made its way onto various college campuses and into the hands of those with a penchant for experimentation. In 1971, Esquire Magazine introduced phreaking to the masses with the article “Secrets of the Little Blue Box” — which made mention of soon-to-be-phreaks and future Apple founders Steve Wozniak and Steve Jobs. But it was the article which appeared in the June 1972 issue of Ramparts Magazine entitles “How to Build a ‘Phone Phreak’s”” Box” which touched off a firestorm of interest in phreaking — and even went so far as to include simple schematics of how to construct your own “black box” used to make and receive free long distance calls.

Eventually, North American phone companies replaced their hardware, as a measure to move forward with digital switching systems (Common Channel Interoffice Signaling), thus eliminating old-school phreaking practices — new systems use separate lines for signalling that phreaks couldn’t get to. Classic phreaking with the 2600 Hz tone continued to work in more remote locations into the 1980’s, but was of little use in North America by the 1990’s. It was the end of an era — Phil Lapsley says it best: “(Phone phreaks) listened to clicks and clunks and beeps and boops to figure out how calls were routed. They read obscure telephone company technical journals. They learned how to impersonate operators and other telephone company personnel. The dug through telephone company trash bins to find ‘secret’ documents. They solved puzzles.”

There’s few things more satisfying than the fortresses of the giant telcos being circumnavigated; and there’s something intriguing about the resourcefulness, the hucksterism, and the full-out charlatanism required in order to use technology to stick it to “the man”.

Next blog — in two week’s time — I’ll be writing about Speaking Clocks or “Time & Temperature”– the automated time-telling services which have been around practically since telephones were invented, and which are rapidly heading the way of the buggy whip.

Thanks for reading!


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