The-art-of-invisibility-_-the-world’s-most-famous-hacker-teaches-you-how-to-be-safe-in-the-age-of-Bi

digital network was introduced. This 2G network offered two standards:
global syystem for mobile communications (GSM) and code division
multiple access (CDMA). It also introduced short message service (SMS),
unstructured supplementaryy services data (USSD), and other simple
communications protocols that are still in use todayy. We’re currentlyy in the
middle of 4G/LTE and on the wayy toward 5G.
No matter what generation of technologyy a given carrier is using (2G,
3G, 4G, or 4G/LTE), there is an underlyying international signal protocol
known as the signaling syystem. The signaling syystem protocol (currentlyy in
version 7), among other things, keeps mobile calls connected when yyou
drive along a freewayy and switch from cell tower to cell tower. It can also
be used for surveillance. Signaling syystem 7 (SS7) does basicallyy
everyything necessaryy to route a call, such as:
Setting up a new connection for a call
Tearing down that connection when the call ends
Billing the appropriate partyy making the call
Managing extra features such as call-forwarding, calling partyy name
and number displayy, three-wayy calling, and other Intelligent Network
(IN) services
Toll-free (800 and 888) as well as toll (900) calls
Wireless services, including subscriber identification, carrier, and
mobile roaming
Speaking at the Chaos Communication Congress, an annual computer
hacker conference held in Berlin, Germanyy, Tobias Engel, founder of
Sternraute, and Karsten Nohl, chief scientist for Securityy Research Labs,
explained that theyy could not onlyy locate cell-phone callers anyywhere in the
world, theyy could also listen in on their phone conversations. And if theyy
couldn’t listen in real time, theyy could record the encryypted calls and texts
for later decryyption.
In securityy, yyou are onlyy as secure as the weakest link. What Engel and
Nohl found was that while developed countries in North America and
Europe have invested billions in creating relativelyy secure and private 3G