August 26, 2004 · Richard Posner
…is the name of a 1998 novel by Dan Brown, the author of The Da Vinci Code. Digital Fortress is a cyberthriller about the National Security Agency (NSA), which monitors and intercepts electronic communications worldwide. In the book as in real life, the agency is concerned with encryption technologies that can prevent it from decoding the communications that it intercepts.(One of the triumphs of modern technology is the unbreakable code; it used to be that even the cleverest codes could, with enough time and effort, be decoded.) The agency would like all such technologies to contain a “backdoor” that would enable it and only it to decode all intercepted messages.
The book has a number of unrealistic features (I very much doubt, for example, that the NSA employs hit men), but it flags a genuine problem, which is that privacy is an equivocal good. This statement will shock many people, for whom “privacy,” like “liberty” and “justice,” signifies an unallowed good. In fact all that “privacy” means, in the case of communications at any rate, is concealment, which obviously can serve bad as well as good purposes; few civil libertarians are so doctrinaire as to deny that there are some situations in which wiretapping of phone conversations is legitimate. So what if telephone or other electronic communications are so effectively encrypted that wiretapping (or wireless tapping) is impossible? It would be another example, analytically symmetrical with that of the use of encryption to protect (and extend) copyright protection, of technology upsetting a balance deliberately struck by the law, in this case between freedom and safety. Hence the case for the back door. The problem is how to control the back door. In the case of conventional, nonencrypted phone conversations, the government has to obtain a warrant to wiretap. But the (unspoken) assumption is that evidence of criminal activity can usually be obtained without wiretapping, then used as the basis for applying to a judicial officer for a warrant to obtain further conclusive evidence. But in the case of foreign intelligence surveillance, the assumption is that winnowing an enormous mass of unfiltered communications may be the only way of obtaining evidence of some terrorist or other enemy threat, and if so then it would be dangerous to forbid the NSA to read intercepted communications without a warrant. But if the NSA has unlimited authority to read communications, then no communications are really private.
My inclination–it is only that; I am not an expert in these matters–would be to let the NSA have its back door. I think that people who worry a lot about invasions of communicative privacy sometimes overlook the fact that communications are never really private. There is always the possibility that the person at the other end of the communication, the person you trust not to disclose the contents of the communication to anyone else, will betray you, or that he will make a copy of the communication and it will come into the hands of someone who wishes you ill. In the case of email, we all know by now that an email message is likely to sit, forever, on several servers and terminals. So communicative privacy is inherently qualified, imperfect, incomplete; and the question is whether knowledge that your communications may be decoded, scanned, and perhaps stored, by the NSA, is going to inhibit you, or inflict psychological distress; and the answer to both questions probably is no.
I don’t doubt that there potential dangers from allowing government surveillance. Think now of the NSA’s interceptions being filed under the names of the participants in the intercepted communication and placed in a database along with other information about each individual, including for example his commuting patterns gleaned from the E-Z Pass database. Eventually there would be an incredibly detailed dossier on every person in the U.S. The value of such dossiers for preventing terrorism and detecting crime would be immense; but so would be the potential political and psychological consequences if every person knew that the government was in effect tracking his every move.