With reports last month that RSA Security worked with the NSA under a $10 million contract to weaken internet security, a number of speakers have withdrawn from the company's annual security conference due to be held next month.
RSA Security, owned by data storage giant EMC, has disputed claims that it intentionally introduced the flawed encryption algorithm, but otherwise has declined to discuss the media report.
The revelation supplemented documents leaked by former NSA contractor Edward Snowden showing that the NSA had tried to weaken internet encryption.
The withdrawals from the highly regarded conference represent early blowback by experts who have complained that the government's surveillance efforts have, in some cases, weakened computer security, even for innocent users.
Some US companies that have agreed or been compelled to turn over customer records to the government have complained that their business relationships with customers in Europe, Asia, and elsewhere are increasingly becoming arduous.
It was not immediately clear whether any researchers who still intended to make presentations at the conference would discuss the subject.
Hugh Thompson, a conference organiser who works for security firm Blue Coat Systems, said the event is "an open venue where people can talk openly about security".
The researchers and experts who have pulled out include Mikko Hypponen, chief research officer of Finland-based antivirus provider F-Secure, and Adam Langley and Chris Palmer, who work on security practices at Google.
Christopher Soghoian, a researcher with the American Civil Liberties Union, said on Tuesday on Twitter that he withdrew from the conference after having "given up waiting for RSA to 'fess up to the truth" regarding its development of the Dual-EC-DRBG algorithm with the NSA.
Organisers have said that next month's conference in San Francisco will host 560 speakers, and that they expect more participants than the 24,000 who showed up last year.