The cover of Newsweek magazine on 27 July 1970 featured an innocent couple being menaced by cameras and microphones and new technologies like computer punch cards and paper tape. The headline hollered "IS PRIVACY DEAD?".

The same question has been posed every few years ever since.

In 1999, Sun Microsystems boss Scott McNally urged us to "get over" the idea we have "zero privacy"; in 2008, Ed Giorgio from the Office of the US Director of National Intelligence chillingly asserted that "privacy and security are a zero-sum game"; Facebook's Mark Zuckerberg proclaimed in 2010 that privacy was no longer a "social norm". And now the scandal around secret surveillance programs like PRISM and the Five Eyes' related activities looks like another fatal blow to privacy. But the fact that cynics, security zealots and information magnates have been asking the same rhetorical question for over 40 years suggests that the answer is No!

PRISM, as revealed by whistle blower Ed Snowden, is a Top Secret electronic surveillance program of the US National Security Agency (NSA) to monitor communications traversing most of the big Internet properties including, allegedly, Apple, Facebook, Google, Microsoft, Skype, Yahoo and YouTube. Relatedly, intelligence agencies have evidently also been obtaining comprehensive call records from major telephone companies, eavesdropping on international optic fibre cables, and breaking into the cryptography many take for granted online.

In response, forces lined up at tweet speed on both sides of the stereotypical security-privacy divide. The "hawks" say privacy is a luxury in these times of terror, if you've done nothing wrong you have nothing to fear from surveillance, and in any case, much of the citizenry evidently abrogates privacy in the way they take to social networking. On the other side, libertarians claim this indiscriminate surveillance is the stuff of the Stasi, and by destroying civil liberties, we let the terrorists win.

Governments of course are caught in the middle. President Obama defended PRISM on the basis that we cannot have 100% security and 100% privacy. Yet frankly that's an almost trivial proposition. It's motherhood. And it doesn't help to inform any measured response to the law enforcement challenge, for we don't have any tools that would let us design a computer system to an agreed specification in the form of, say "98% Security + 93% Privacy". It's silly to us the language of "balance" when we cannot measure the competing interests objectively.

Politicians say we need a community debate over privacy and national security, and they're right (if not fully conscientious in framing the debate themselves). Are we ready to engage with these issues in earnest? Will libertarians and hawks venture out of their respective corners in good faith, to explore this difficult space?

I suggest one of the difficulties is that all sides tend to confuse privacy for secrecy. They're not the same thing.

Privacy is a state of affairs where those who have Personal Information (PII) about us are constrained in how they use it. In daily life, we have few absolute secrets, but plenty of personal details. Not many people wish to live their lives underground; on the contrary we actually want to be well known by others, so long as they respect what they know about us. Secrecy is a sufficient but not necessary condition for privacy. Robust privacy regulations mandate strict limits on what PII is collected, how it is used and re-used, and how it is shared.

Therefore I am a privacy optimist. Yes, obviously too much PII has broken the banks in cyberspace, yet it is not necessarily the case that any "genie" is "out of the bottle".
If PII falls into someone's hands, privacy and data protection legislation around the world provides strong protection against re-use. For instance, in Australia Google was found to have breached the Privacy Act when its StreetView cars recorded unencrypted Wi-Fi transmissions; the company cooperated in deleting the data concerned. In Europe, Facebook's generation of tag suggestions without consent by biometric processes was ruled unlawful; regulators there forced Facebook to cease facial recognition and delete all old templates.

We might have a better national security debate if we more carefully distinguished privacy and secrecy.

I see no reason why Big Data should not be a legitimate tool for law enforcement. I have myself seen powerful analytical tools used soon after a terrorist attack to search out patterns in call records in the vicinity to reveal suspects. Until now, there has not been the technological capacity to use these tools pro-actively. But with sufficient smarts, raw data and computing power, it is surely a reasonable proposition that - with proper and transparent safeguards in place - population-wide communications metadata can be screened to reveal organised crimes in the making.

A more sophisticated and transparent government position might ask the public to give up a little secrecy in the interests of national security. The debate should not be polarised around the falsehood that security and privacy are at odds. Instead we should be debating and negotiating appropriate controls around selected metadata to enable effective intelligence gathering while precluding unexpected re-use. If (and only if) credible and verifiable safeguards can be maintained to contain the use and re-use of personal communications data, then so can our privacy.

For me the awful thing about PRISM is not that metadata is being mined; it's that we weren't told about it. Good governments should bring the citizenry into their confidence.

Are we prepared to honestly debate some awkward questions?

  • Has the world really changed in the past 10 years such that surveillance is more necessary now? Should the traditional balances of societal security and individual liberties enshrined in our traditional legal structures be reviewed for a modern world?
  • Has the Internet really changed the risk landscape, or is it just another communications mechanism. Is the Internet properly accommodated by centuries old constitutions?
  • How can we have confidence in government authorities to contain their use of communications metadata? Is it possible for trustworthy new safeguards to be designed?

Many years ago, cryptographers adopted a policy of transparency. They have forsaken secret encryption algorithms, so that the maths behind these mission critical mechanisms is exposed to peer review and ongoing scrutiny. Secret algorithms are fragile in the long term because it's only a matter of time before someone exposes them and weakens their effectiveness. Security professionals have a saying: "There is no security in obscurity".

For precisely the same reason, we must not have secret government monitoring programs either. If the cases is made that surveillance is a necessary evil, then it would actually be in everyone's interests for governments to run their programs out in the open.