Abstract
Digital Video Broadcasting (DVB) is a set of standards for digital television. DVB supports the encryption of a transmission using the Common Scrambling Algorithm (DVB-CSA). This is commonly used for PayTV or for other conditional access scenarios. While DVB-CSA support 64 bit keys, many stations use only 48 bits of entropy for the key and 16 bits are used as a checksum. In this paper, we outline a time-memory-tradeoff attack against DVB-CSA, using 48 bit keys. The attack can be used to decrypt major parts a DVB-CSA encrypted transmission online with a few seconds delay at very moderate costs. We first propose a method to identify plaintexts in an encrypted transmission and then use a precomputed rainbow table to recover the corresponding keys. The attack can be executed on a standard PC, and the precomputations can be accelerated using GPUs. We also propose countermeasures that prevent the attack and can be deployed without having to alter the receiver hardware.
Original language | English |
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Title of host publication | Research in Cryptology |
Subtitle of host publication | 4th Western European Workshop, WEWoRC 2011, Weimar, Germany, July 20-22, 2011, Revised Selected Papers |
Editors | Frederik Armknecht, Stefan Lucks |
Publisher | Springer |
Pages | 45-61 |
Number of pages | 17 |
ISBN (Electronic) | 978-3-642-34159-5 |
ISBN (Print) | 978-3-642-34158-8 |
DOIs | |
Publication status | Published - 2011 |
Event | 4th Western European Workshop 2011 - Weimar, Germany Duration: 20 Jul 2011 → 22 Jul 2011 Conference number: 4 |
Publication series
Name | Lecture Notes in Computer Science |
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Publisher | Springer |
Volume | 7242 |
Conference
Conference | 4th Western European Workshop 2011 |
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Abbreviated title | WEWoRC 2011 |
Country/Territory | Germany |
City | Weimar |
Period | 20/07/11 → 22/07/11 |