The Cryptographic Imagination: Secret Writing from Edgar Poe to the Internet (Parallax: Re-visions of Culture and Society) [Hardcover]

Unfortunately, Rosenheim's attempts at discussion of technical matters are nearly always marked by severe misunderstandings of the mathematics and physics involved. For example, consider his definition of quantum cryptography, which appears in the glossary:

"A form of cryptography in which, under certain experimental conditions, pairs of photons may be created that exert an influence over one another that cannot be explained by quantum mechanics. Measuring the polarization of one particle immediately and identically changes the spin on its antiparticle. Such polarization takes place regardless of the relative positions of the two particles in the universe, in a result that seems to violate the second law of classical theory. It is theoretically possible that a stream of such polarized photons could be used to encipher messages that could be sent over space in literally no time at all."

There are so many errors in just these four sentences that it is difficult to know where to begin. First of all, the behavior of entangled photon pairs is, contrary to the claim, perfectly explicable through quantum mechanics. Second, practical quantum cryptography is not currently based on entangled photon pairs --- although Ekert did propose such a scheme --- but a different mechanism proposed much earlier by Wiesner and Bennett & Brasssard. Third, the reference to the ``second law'' is, of course, utter nonsense.

Other blunders in _The Cryptographic Imagination_ include conflating monkeys and apes, misstating Zipf's law, wildly over-estimating the amount of pornography on the Internet, misstating the name of the Usenet newsgroup "alt.sexual.abuse.recovery", and comically misspelling the name of one of the inventors of RSA as "Ronald Rivers". Rosenheim even makes mistakes in his own field: he claims that Georges Perec's book _La Vie: Mode d'Emploi_ was written without the letter "e", when in fact it is another book of Perec entitled _La Disparition_.

This is not to say that I didn't get anything out of Rosenheim's book. I was intrigued to learn about Lizzie Doten, a 19th century mystic who "channeled" ersatz poems of Poe and other writers such as Shakespeare and Burns. But the book is marred by the usual postmodernist excesses: making much of tenuous or nonexistent connections, second-rate wordplay (the series in which _The Cryptographic Imagination_ is published is entitled "re-visions of culture and society"; among postmodernists, this sort of gratuitous hyphen insertion is apparently considered essential), and opaque exposition. Consider the following two examples:

"When I claim that Poe helped end World War II, the `Poe' in that sentence represents both a particular author and the literary genre he helped create and for which he serves as a synecdoche." [p. 15]

"Such a homeopathic technique for the creation of mysteries produces highly cathected readers; the surface of the cipher produces a crypt in us, which we proceed to fill with our imagination, just as the semantic vacuity of Khumnhotep's [sic] glyphs contextually signified Khumnhotep's [sic] power and his resistance to comprehension." [p. 48]

_The Cryptographic Imagination_ will be of little interest to anyone wanting to learn about cryptography. In fact, I can scarcely think of a reason to read it, except perhaps to see an example of what passes for scholarly work in some academic disciplines.