Wednesday, July 19, 2017

Open Letter to my Congressman


In my forty years in information security I have come to have many colleagues in the intelligence community.  I find them to be brilliant and noble.  I have also found them to be myopic, artful, and zealous.  I have watched their testimony before both the House and Senate judiciary committees.  While I have been impressed by their testimony, I have been less impressed by the questioning.   The testimony has been carefully rehearsed and very consistent.  Where the questioning has not been sympathetic, it has been inept.  Even those legislators who recognize that the testimony is misleading are prevented by secrecy and decorum from asking the questions that might really inform the citizens or even saying so when a witness lies under oath. 

·         Here is a short list of questions that I would like put to the administration to answer under oath.

  • Does GCHQ target American citizens on behalf of the US government?  What did we get for our $152M? 
  • Does the NSA target citizens of the United Kingdom?  Does it do so on behalf of the UK government? 
  • What programs, besides the collection of all telephone call records, does the NSA operate under USA Patriot Act, Section 215?  What programs, other than PRISM, does it operate under the FISA, Section 702?  Are we going to be surprised by more revelations?   
  • NSA has admitted that a query to the call records database implicates not only those connected directly to the "seed" number but all those associated with it to "three hops."  What is the largest number of phone numbers implicated by any single query?  How many subscribers have been implicated by the hundreds of queries made since the inception of the program?  Is it possible that there is any American citizen  that has not been swept up in this huge drag net?
  • Given the density of modern digital storage, e.g., a terabyte in a shirt pocket for $100, what is NSA storing that requires 24 acres of floor space in Utah?  
  • What percentage of the e-mail that crosses our borders does NSA collect?  Store?  Analyze?  Disseminate to other agencies of government?  
  • Given the demonstrations by Edward Snowden and Bradley Manning as to the breadth and depth of their access, how can we rely upon the assurances of NSA  that they can protect us from abuse of the information they collect?  Doesn't the mere collection of all this information invite, not to say guarantee, abuse?
  • Doesn't the mammoth budget ($75B in 2t012?) of NSA justify the conclusion that NSA operates on the premise that "Because we can, we must," and without any regard for efficiency?   Are they not spending far more than doing nothing would cost?
  • Does not the Bush "Warrantless Surveillance Program" demonstrate that citizens cannot rely upon bureaucrats and spies to protect us from over-zealous, not to say rogue, politicians?  Are we building capabilities now that will empower politicians of the future? 
  • Does the NSA require a warrant before they target US citizens on behalf of the FBI?  Secret Service? DEA?  MI5?  MI6?  
  • Does the NSA protect American citizens from surveillance by their peers and colleagues in other nations?  
  •  Is information passed to the FBI by NSA ever, usually, sufficient for the issuance of a wiretap warrant?  A National Security Letter?  
  •  Do the intelligence agencies selectively share intelligence with legislators in order to curry support?

Wednesday, July 5, 2017

The Coming Quantum Computing Crypto Apocalypse

Modern media, both fact and fiction, loves the Apocalypse and the Dystopian future.  The Quantum Apocalypse is just one example but one close to the subject of this blog.  It posits that the coming revolution called quantum computing will obsolete modern encryption and destroy modern commerce as we have come to know it.  It was the hook for the 1992 movie Sneakers starring Robert Redford, Sydney Poitier, Ben Kingsley, and River Phoenix.

This entry will tell the security professional some useful things about the application of Quantum Mechanics to information technology in general, and Cryptography in particular, that will help equip him for, and enlist him in, the effort to ensure that commerce, and our society that depends upon it, survive.  Keep in mind that the author is not a Physicist or even a cryptographer.  Rather he is an octogenarian, a computer security professional, and an observer of and commentator on the experience that we call modern Cryptography beginning with the Data Encryption Standard.

For a description of Quantum Computing I refer you to Wikipedia.  For our purpose here it suffices to say that it is very fast at solving certain classes of otherwise difficult problems.  One of these problems is to find the factors of the product of two prime numbers, the problem that one must solve to find the message knowing the cryptogram and the public key or the private key knowing the message, the cryptogram, and the public key in the RSA crypto systems.

This vulnerable algorithm is the one that we rely upon for symmetric key exchange in our infrastructure.  In fact, because it is so computationally intensive, that is the only thing we use it for.

In theory, using quantum computing, one might find the factors almost as fast as one could find the product, while the cryptographic cover time of the system relies upon the fact that the former takes much longer than the latter.  Cryptographers would certainly say that, by definition, at least in theory, the system would be "broken."  However, the security professional would ask about the relative cost of the two operations.  While the former can be done by any cheap computer, the latter can only be done quickly by much more rare and expensive "quantum" computers.

Cryptanalysis is one of the applications that has always supported cutting edge computing. One of the "Secrets of ULTRA" was that we invented modern computing in part to break the Enigma system employed by Germany.  ULTRA was incredibly expensive for all that.  While automation made ULTRA effective, it was German key management practices that made it efficient.    On the other hand, the modern computer made commercial and personal cryptography both necessary and cheap.

One can be certain that NSA is supporting QC research and will be using one of the first practical implementations for cryptanalysis.  They will be doing it literally before you know it and exclusively for months to years after that.

Since ULTRA, prudent users of cryptography have assumed that, at some cost, nation states (particularly the "Five Eyes," Russia, China, France, and Israel) can read any message that they wish. However, in part because the cost of reading one message includes the cost of not reading others, they cannot read every message that they wish.

The problem is not that Quantum Computing breaks Cryptography, per se, but that it breaks one system on which we rely.  It is not that we do not have QC resistant crypto but that replacing what we are using with it will take both time and money.  The faster we want to do it, the more expensive it will be.  Efficiency demands that we take our time; effectiveness requires that we not be late.

By some estimates we may be as much as 10 years away from an RSA break but then again, we might be surprised.  One strategy to avoid the consequences of surprise is called "crypto agility."  It implies using cryptography in such a way that we can change the way we do it in order to adapt to changes in the threat environment.

For example, there are key exchange strategies that are not vulnerable to QC.  One such has already been described by the Internet Engineering Task Force (IETF).  It requires a little more data and cycles than RSA but this is more than compensated for by the falling cost of computing.  It has the added advantage that it can be introduced in a non-disruptive manner, beginning with the most sensitive applications.

History informs us that cryptography does not fail catastrophically and that while advances in computing benefit the wholesale cryptanalyst, e.g., nation states, before the commercial cryptographer, in the long run they benefit the cryptographer orders of magnitude more than the cryptanalyst.  In short, there will be a lot of work but no "Quantum Apocalypse."  Watch this space.