In 2007, Koblitz published "The Uneasy Relationship Between Mathematics and Cryptography," which contained some controversial statements about provable security and other topics. Researchers Oded Goldreich, Boaz Barak, Jonathan Katz, Hugo Krawczyk, and Avi Wigderson wrote letters responding to Koblitz's article, which were published in the November 2007 and January 2008 issues of the journal. Katz, who is coauthor of a highly regarded cryptography textbook, called Koblitz's article "snobbery at its purest"; and Wigderson, who is a permanent member of the Institute for Advanced Study in Princeton, accused Koblitz of "slander."