Description
As phones are used for more and more sensitive operations (such as bank transfers for example), there is a great necessity to design and deploy protocols that can ensure the security of such transactions, even in cases when the phone has been compromised. In order to accomplish that, Android in collaboration with Google have worked on a protocol called Android Protected Confirmation. The idea behind this protocol is to give to any application a way to leverage the security of the phone's Trusted Execution Environment (TEE) to sign operations without needing the application code to be directly included in the TEE. This allows a wider usability as the code of the application does not need to be verified to use the protocol. The protocol's main claim is the following: in order for a message to be signed, it must first have been seen and accepted by the user, even in presence of an adversary with root privileges. This gives better guaranties to the server (for example the bank) that the requested transaction is indeed demanded by the user.
Our analysis of this protocol allowed us to find two attacks. The first happens at the registration phase and allows an attacker to register credentials under the victim’s identity. The second one at the transaction phase allows a corrupted rich, non-secure, operating system to send signed messages to an unintended server. We also implemented a variation of the second attack on a Google Pixel 6. Then using the Universal Composability framework, we proposed an ideal functionality for Protected Confirmation and we proved fixes for both attacks.
Practical infos
Next sessions
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Vers l’émergence d’un droit européen pour la Blockchain : Une approche sous l’angle de la Privacy et de l’encadrement des crypto-actifs
Speaker : Damien Franchi - Univ Rennes, IODE
La Blockchain, technologie derrière Bitcoin, fait l’objet d’un encadrement juridique de plusen plus important, en particulier de la part de l’Union européenne. Curieusement, le mot« Blockchain » n’apparaît pas dans les textes l’encadrant. Les expressions « technologie deregistres distribués » (Distributed ledger technology, DLT), ou, parfois, « registreélectronique » lui sont plutôt privilégiées.[…]-
SoSysec
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Law
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Blockchain and digital currencies: between European regulation and technological challenges
Speaker : Loïc Miller - CentraleSupélec
As the European Union develops a legal framework for crypto-assets and data protection, the technological question underlying the emergence of a genuine digital currency remains open. Blockchain today stands as an interdisciplinary field of study at the crossroads of computer science, economics, and law. This presentation will place the ongoing regulatory framework in perspective with the[…]-
SoSysec
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Distributed systems
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Hardware-Software Co-Designs for Microarchitectural Security
Speaker : Lesly-Ann Daniel - EURECOM
Microarchitectural optimizations, such as caches and speculative out-of-order execution, are essential for achieving high performance. However, these same mechanisms also open the door to attacks that can undermine software-enforced security policies. The current gold standard for defending against such attacks is the constant-time programming discipline, which prohibits secret-dependent control[…]-
SoSysec
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Hardware/software co-design
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Micro-architectural vulnerabilities
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