"There is a good chance that large quantum computers can be built within the next 20 years.  This would be a nightmare for IT security if there are no fully developed, implemented, and standardized post-quantum signature schemes."

Prof. Johannes Buchmann, et al, “Post-Quantum Signatures”, Oct 2004, Technische Universität Darmstadt

"Given their power to intercept and disrupt secret communications, it is not surprising that quantum computers have the attention of various U.S. government agencies.  The National Security Agency, which supports research in quantum computing, candidly declares that given its interest in keeping U.S. government communications secure, it is loath to see quantum computers built. On the other hand, if they can be built, then it wants to have the first one.”

Prof Seth Lloyd of MIT, MIT Review 2008

“Briefly and simply, assurance work makes a user or a creditor more confident that the system works as intended without flaws, without surprises, even in the presence of malice.” … “The major shortfall is absence of assurance or safety mechanisms in software.  If my car crashed as often as my computer does, I’d be dead by now.”

Brian Snow, Former Technical Director of the US National Security Agency (NSA), "We need Assurance", AusCERT 2008