Logical Formalisation and Analysis of the Mifare Classic Card in PVS

摘要

The way that Mifare Classic smart cards work has been uncovered recently [6,8] and several vulnerabilities and exploits have emerged. This paper gives a precise logical formalisation of the essentials of the Mifare Classic card, in the language of a theorem prover (PVS). The formalisation covers the LFSR, the filter function and (parts of) the authentication protocol, thus serving as precise documentation of the card's ingredients and their properties. Additionally, the mathematics is described that makes two key-retrieval attacks from [6] work.