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The cryptography behind electronic passports
Modern passports are embedded devices with a filesystem, access controls, and cryptography. These electronic passports contain a chip with personal data and use cryptographic measures to prevent unauthorized access, forgery, and copying. The ICAO defines standards for these passports, focusing on data structure and security. The passport's filesystem includes master files, dedicated files, and elementary files containing binary data. The eMRTD application stores personal information and security data in data groups, mirroring data printed on the passport. Electronic passports face threats like unauthorized reading, eavesdropping, forgery, and copying, depending on the attacker's physical access. Cryptographic mechanisms, including legacy protocols like BAC, aim to provide confidentiality and prevent forgery, however BAC has serious flaws. Passive authentication prevents forgery by verifying a digital signature from the issuing country. Active authentication adds a layer to prevent copying by using a private key within the passport. Extended Access Control (EAC) improves security with chip and terminal authentication, and PACE replaces BAC to eliminate its weaknesses.
