Guardian article says:
Three million Britons have been issued with the new hi-tech passport, designed to frustrate terrorists and fraudsters. So why did Steve Boggan and a friendly computer expert find it so easy to break the security codes?
The Home Office has adopted a very high encryption technology called 3DES – that is, to a military-level data-encryption standard times three. So they are using strong cryptography to prevent conversations between the passport and the reader being eavesdropped, but they are then breaking one of the fundamental principles of encryption by using non-secret information actually published in the passport to create a ‘secret key’. That is the equivalent of installing a solid steel front door to your house and then putting the key under the mat.”