As South Africa’s parliament finalises its debate on the Protection of State Information Bill, [pdf] it is important to take a step back from the detail and go back to basic principles.

There are two starting points for an assessment of the Bill.  First, there is a place in a democracy for legislation that optimally balances on the one hand openness and transparency in the work of public bodies, and the right of citizens to access information, and on the other hand, the legitimate governmental objective in protecting national security.

Second, in principle the norm should be openness and transparency about political matters, and therefore restrictions on openness should only be permissible in our democracy in exceptional circumstances.

If one proceeds from these starting points – that a constitutional balancing exercise is necessary between these two protectable interests, but that the norm is that of openness and transparency – the next question becomes how to craft the detail of legislation so that at once each of those interests is both protected, but that openness is only limited to the minimal extent possible.

A constitutional national security law – one that properly balances these two interests – must contain at least five essential ingredients.

The first is that the definition of “national security” must be narrowly tailored.  It will not do to have, as the first draft of the Bill did, a broad conception of “national interest” which allows almost anything to be classified.  Such a position would of course result in over classification and hence the unjustifiable censorship of political speech.  The current draft of the Bill at least contains a narrower conception of national security, though overbreadth problems remain with some of the categories of information that are covered.

The second essential ingredient is that classification must only be permitted if there is a likelihood of harm to national security. It should not be permissible to classify based on speculative harm.  It would be far too easy to permit a classifier to stamp a document as “top secret”, “secret” or “confidential”, if the threshold test is that some harm to national security may conceivably arise if the information is made public. South African constitutional law requires that there must be a real risk of prejudice to national security before it can be kept from the public’s view.  The original Bill allowed for classification based on speculative harm, and at least the current draft cures this.

But classifiers will still find it impossible, based on the current Bill, to properly distinguish between the categories of classification.  For instance, information must be classified as “secret” ifits disclosure “it is likely or could reasonably be expected to cause serious demonstrable harm to national security”.  But information must be classified as “top secret” if disclosure “is likely or could reasonably be expected to demonstrably cause serious or irreparable harm to national security”.  These two categories blur to such an extent as to be entirely impractical, with serious consequences for the rule of law.

The third feature of a constitutional national security law is recognition of the principle of redaction, as well as the need to include processes for the declassification of classified information. The principle of redaction means that the classifier must apply his or her mind to the totality of the information sought to be classified and only classify those aspects of information which truly harm national security. The rest should be accessible to the public.  For instance, a document might be released to the public with the identities of confidential informants redacted, as opposed to keeping the entire document secret.  There is no explicit recognition of this principle in the current version of the Bill.

What is also required in a constitutional national security law is a reasonable process for the declassification of classified information.  There should be automatic declassification after a number of years of certain classified information, as well as consideration of whether classified information should be declassified on the request of any person. By and large, the current version of the Bill broadly caters for some declassification processes, although there is certainly room for major improvement in relation to how these processes are to work, particularly where a citizen requests access to classified information.

The fourth ingredient for a constitutional national security law is necessary where the disclosure of classified information is to be criminalised, as with our Bill.  In addition to the usual defences that are available in criminal law, the role of whistleblowing in the public interest must be recognised. As Cosatu, the leading trade union in South Africa, has put it in its latest submissions, there is a need for a safeguard that would act as a counterbalance to legitimate restrictions on national security. Our own painful apartheid history has taught us that corruption, criminality and other misdeeds have often been hidden under the cloak of classification, ostensibly to protect national security.  And South Africa’s recent history also highlights the need to protect messengers who, dressed in their democratic best, ventilate information which the public has a right to know.

So there should be a mechanism for someone who has been leaked classified information which ought to be made public in the public interest, to inform the public without facing criminal sanction.  Although there has been some movement by parliament in this regard, there is still no adequate safeguard for the publication of information that serves the public interest.

The final ingredient, which is also sorely lacking in the current Bill, is recognition that once information is in the public domain, it makes little sense to criminalise its repetition.  And of course this consideration applies with even greater force in the digital age, where information can go viral in the space of a few minutes.

The constitutional point to make in this regard is that once the horse has bolted, and information that has been classified is widely available around the country, if not the world, it cannot serve the administration of justice to prosecute those who republish the information.  There may well be a case for prosecuting the original leaker of the classified information, but the law will truly become an ass, as an English judge once said in relation to this issue, if information which is being downloaded all over the world cannot be read or further disseminated in South Africa.

These, then, are the five ingredients which at minimum a constitutional national security law should contain. Although some of these ingredients have been included in the latest version of the Bill, without including the others, the end-product will necessarily be half-baked and indigestible.

Dario Milo, partner at Webber Wentzel.  An earlier version of this article appeared in The Star newspaper in South Africa.  Follow Dario Milo on twitter @dariomilo