History of FBI doing TCSM

Courtesy of Cryptome’s link distribution, we get to review http://www.governmentattic.org/5docs/FBI-62-HQ-97308-PhoneSecurity_1952-1995.pdf. We get a glimpse into the mind of 1952 (an era when crypto on land lines was very limited, indeed). We get to see how the US tapped and how it worked with the phone company to tap others – in the course of determining that standard US techniques for taps were not present (2-wire pair line tampering, inductive tapping of the 2-wire pair on local telephone pole, tapping of the “multiplying line” extensions).  Let’s not  forget jus “how physical” was telephony, in 1952.

via yorkporc.wordpress.com