Two members of congress are inquiring about a potential mobile network vulnerability to the Department of Homeland Security (DHS).  Last week, Senator Ron Wyden (D-OR) and Representative Ted Lieu (D-CA) authored a letter to DHS Secretary John Kelly about security risks in Signaling System 7 (SS7) protocol.

SS7 protocol is used by global telecom networks to route calls and texts between users. Digital privacy advocates and experts have voiced concern about the system’s vulnerability to hacking; some saying it’s inherently insecure. A 2014 study (BY WHOM?) indicated hackers can insert themselves two different ways into a device by exploiting the SS7 system. Doing so allows hackers to redirect calls, messages and decrypt information in correspondence.

Senator Wyden’s and Representative Lieu’s letter to the DHS asks how the department has informed the public of these risks and how the department plans to protect the private sector and government officials from potential SS7 surveillance.

“We suspect that most Americans simply have no idea how easy it is for a relatively sophisticated adversary to track their movements, tap their calls, and hack their smartphones,” Wyden and Lieu wrote.

To read Sen. Wyden and Rep. Lieu’s full letter, visit here.