By Raphael Satter
WASHINGTON (Reuters) - Phone companies are denying the U.S. military's requests for data about vulnerabilities in the American telecom system, according to a letter released Wednesday.
In answers provided to Democratic Senator Ron Wyden, the Pentagon said it had requested the results of digital security tests and audits from the carriers it contracts with for telecommunications services but was turned down on the grounds that "they are considered attorney-client privileged information."
In a letter co-signed with Republican Senator Eric Schmitt, Wyden said that the answer wasn't acceptable.
While the Pentagon was among the largest buyers of wireless telephone service in the United States, "it has failed to use its purchasing power to require cyber defenses and accountability from wireless carriers," the letter said.
The carriers weren't identified by name in the military's responses, but AT&T (NYSE:T), Verizon (NYSE:VZ), and T-Mobile are among those that provide commercial wireless service for unclassified use, according to the letter.
AT&T, Verizon, and T-Mobile didn't immediately return messages seeking comment. The Pentagon didn't immediately return an email.
The security of American telecommunications - particular over commercial carriers - has come into focus following a series of dramatic intrusions blamed on Chinese hackers.
U.S. officials have previously alleged that a group of hackers dubbed "Salt Typhoon" stole limited telephone audio intercepts, along with a larger tranche of call record data. Officials have said those records mainly concerned people in the Washington area.
Later Thursday senators are due to receive a classified briefing on Salt Typhoon and its impact on U.S. data.
Chinese officials have previously described the allegations as disinformation and that Beijing "firmly opposes and combats cyber attacks and cyber theft in all forms."