Researchers at a computer security conference in Washington, D.C. this week detailed a method for dramatically reducing the cost and time needed to crack the security that prevents eavesdropping of GSM-based mobile phones. The weaknesses in the GSM encryption technology — a 64-bit scheme known as A5/1 — were first detailed nearly a decade ago, but cracking the code has generally required a great deal of patience and some very expensive hardware (with hardware costs alone exceeding $1 million). U.S. based GSM carriers — including AT&T and T-Mobile — as well as most European GSM providers are among the dozens of mobile providers and billions of handsets worldwide using A5/1 as their privacy standard. Most of the previously detailed methods for cracking A5/1 encrypted GSM communications involved “active attacks,” injecting data packets into the carrier’s system or circumventing the encryption altogether by tricking a nearby target’s phone into connecting to