'Free-of-Charge' Tariff. Hacking Coin-Operated Telephone at PHDays

Due to the fact that Positive Hack Days is a forum devoted to the issues of practical IT security, the competitive program contained competitions of practical nature (for example, a contest related to searching information hidden in the Internet and hash cracking).

One of the competitions, where not only your head but hands could work, was a contest named 2600, in the course of which the participants had an opportunity to demonstrate their skills in phreaking and to hack a coin-operated telephone. Any visitor of Positive Hack Days could partake in the competition. The participants were to call a predefined number from a coin-operated telephone using tokens as the means of payment and then extract the used token and give it back to the organizers.

Everyone could get ready for the competition by reading this excellent blog post [RU].

To make this contest possible, an old payphone made in 1990s was bought. It did not work properly – a connection could be established without coins. To fix it, we screw a coin-box, compatible with modern coins in the denomination of two Russian rubles, onto the device.

We had to connect the telephone to an office telephone switch to check its workability – everything functioned perfectly. Then we bought a very simple telephone switch to make the coin-operated telephone work properly during the forum as well and connected these two devices on the platform of the Digital October Center.

The participants were provided with special tokens with PHDays symbols and a small hole. The PHDays token weighed as a coin in denomination of two Russian rubles.

A beautiful model was sitting next to the telephone at the forum to explain the contest rules and technical details of freaking as it is done in Russia. Her assistance was especially useful when foreign participants of the forum studied the strange device and tried to understand why a blue box did not work upon pulse dialing. Of course, there always was a crowd of people wishing not only to participate in the competition but to chat with the beauty as well :)

The winners received prizes and gifts – everything as it should be done :)The competition aroused much interest and was even covered on CNewsTV [RU]:



The 2600 competition will be certainly held at Positive Hack Days next year!