During the hearing, I described how I had been hacking into phone companies for years, including Sprint. I explained that the CALRS system Sprint used for testing was similar to Pacific Bell’s SAS, but with what I thought was even better security: anyone trying to access the remote CALRS test units in each central office had to give the correct response to a challenge in order to get access. The system was programmed with a hundred different challenges—double digits from 00 to 99, each of which had its own response of four hex characters such as b7a6 or dd8c. Hard to crack... except through wiretapping or social engineering.