Economy class crypto: Exploring weak cipher usage in avionic communications via ACARS

Conference item

Recent research has shown that a number of existing wireless avionic systems lack encryption and are thus vulnerable to eavesdropping and message injection attacks. The Aircraft Communications Addressing and Reporting System (ACARS) is no exception to this rule with 99% of the traffic being sent in plaintext. However, a small portion of the traffic coming mainly from privately-owned and government aircraft is encrypted, indicating a stronger requirement for security and privacy by those users. In this paper, we take a closer look at this protected communication and analyze the cryptographic solution being used. Our results show that the cipher used for this encryption is a mono-alphabetic substitution cipher, broken with little effort. We assess the impact on privacy and security to its unassuming users by characterizing months of real-world data, decrypted by breaking the cipher and recovering the keys. Our results show that the decrypted data leaks privacy sensitive information including existence, intent and status of aircraft owners.

Authors: Smith, M; Moser, D; Strohmeier, M; Lenders, V; Martinovic, I

• Publication status: Published
• Peer review status: Reviewed (other)
• Publisher: Springer
• Host title: International Conference on Financial Cryptography and Data Security: Financial Cryptography and Data Security
• Journal: International Conference on Financial Cryptography and Data Security 2017
• Volume: 10322
• Pages: 285-301
• Series: Lecture Notes in Computer Science
• Publication date: 2017-12-23
• Acceptance date: 2017-01-13
• DOI: 10.1007/978-3-319-70972-7_15
• ISBN: 9783319709727