It took a group of 4,000 teams using tens of thousands of computers linked over the Internet 210 days to crack the code. The cracked key challenge is the fourth of 13 challenges presented by the company since January of this year. The third, broken in June, was also a 56-bit key. The other 12 key challenges use the RC5 standard. The remaining nine key challenges increase in strength in increments of 8 bits each.
Key bits increase exponentially, each single bit doubling the key's strength.
In the case of 56-bit encryption, that amounts to more than 72 quadrillion, or 72,057,594,037,927,936, possibilities. The right combination was found after 47 percent of the possibilities had been tried. RSA and other encryption advocates want the government to approve the unrestricted export of 128-bit keys. They argue that U.S. companies are at a disadvantage to competitors in Germany, Ireland, Japan, and other countries with fewer or no encryption restrictions. Congress has been engaged in a pitched battle for more than a year to ease export limits on encryption.