NYTimes | This past January, Laura Poitras received a curious e-mail from an
anonymous stranger requesting her public encryption key. For almost two
years, Poitras had been working on a documentary about surveillance, and
she occasionally received queries from strangers. She replied to this
one and sent her public key — allowing him or her to send an encrypted
e-mail that only Poitras could open, with her private key — but she
didn’t think much would come of it.
The stranger responded with instructions for creating an even more
secure system to protect their exchanges. Promising sensitive
information, the stranger told Poitras to select long pass phrases that
could withstand a brute-force attack by networked computers. “Assume
that your adversary is capable of a trillion guesses per second,” the
stranger wrote.
Before long, Poitras received an encrypted message that outlined a
number of secret surveillance programs run by the government. She had
heard of one of them but not the others. After describing each program,
the stranger wrote some version of the phrase, “This I can prove.”
Seconds after she decrypted and read the e-mail, Poitras disconnected
from the Internet and removed the message from her computer. “I thought,
O.K., if this is true, my life just changed,” she told me last month.
“It was staggering, what he claimed to know and be able to provide. I
just knew that I had to change everything.”
Poitras remained wary of whoever it was she was communicating with. She
worried especially that a government agent might be trying to trick her
into disclosing information about the people she interviewed for her
documentary, including Julian Assange, the editor of WikiLeaks. “I
called him out,” Poitras recalled. “I said either you have this
information and you are taking huge risks or you are trying to entrap me
and the people I know, or you’re crazy.”
The answers were reassuring but not definitive. Poitras did not know the
stranger’s name, sex, age or employer (C.I.A.? N.S.A.? Pentagon?). In
early June, she finally got the answers. Along with her reporting
partner, Glenn Greenwald, a former lawyer and a columnist for The
Guardian, Poitras flew to Hong Kong and met the N.S.A. contractor Edward
J. Snowden, who gave them thousands of classified documents, setting
off a major controversy over the extent and legality of government
surveillance. Poitras was right that, among other things, her life would
never be the same.
