Apple’s fight with the F.B.I. has added to that tension, and a number of other tech companies are expected in the coming days to file court briefs in support of Apple. Among their fears is that creating the software to break into the iPhone could create a backdoor that could be used repeatedly by law enforcement or the spy agencies of other countries.

The director of the National Security Agency, Admiral Michael S. Rogers, also attempted a conciliatory tone at the RSA event. Admiral Rogers did not speak to the Apple case, or even mention the word encryption, but repeatedly emphasized the need for partnership and dialogue to fight cyberthreats. “I implore all of us to be part of that constructive dialogue,” he said. “It’s time to stop talking past each other.”

In a speech made nearby at San Francisco’s Commonwealth Club, Defense Secretary Ashton B. Carter acknowledged that encryption had been a “hot topic here in the Bay Area,” but said he could not address the Apple case because of the ongoing litigation. Instead, he noted that the Pentagon had a vested interest in strong encryption and that the Defense Department is “the largest user of encryption in the world.”

Security experts in the tech industry may not be so quick to embrace conciliation. “You’re opening a can of worms,” Ron Rivest, a cryptographer and professor at the Massachusetts Institute of Technology, told a separate RSA audience.

“The systems we have are so fragile that trying to have extra keys, or extra ways in, or ways to take them apart is asking for all kinds of trouble,” Mr. Rivest said. “The good of the country depends on having strong security.”

Other cryptographers on the panel with Mr. Rivest agreed, with one notable exception: Adi Shamir, an Israeli cryptographer and co-inventor, with Mr. Rivest and Len Adleman, of the RSA encryption algorithm that became the namesake of the annual security conference.

Mr. Shamir argued that Apple had “goofed” by not complying in the San Bernardino case and for not anticipating that the F.B.I. would ask for help to crack the shooter’s iPhone password.

“Even though Apple helped in countless numbers of previous cases, they decided not to comply this time,” Mr. Shamir said. “My advice would have been, comply this time, and wait for a better test case when the case is not so clearly in favor of the F.B.I.”