Reading the Crypto Classics: Chaum: “Untraceable Electronic Mail, Return Addresses, and Digital Pseudonyms”

10.06.2020 10:00-11:00

Speaker: Olga Sanina, TU Darmstadt, Cryptoplexity Group | Location: Online

Organizer: Christian Janson


This talk is the third one in the seminar series „Reading the Crypto Classics“ for the very special summer term 2020. The idea of this seminar is to jointly read classical milestone papers in the area of cryptography, to discuss their impact and understand their relevance for current research areas. The seminar is running as an Oberseminar, but at the same time meant to be a joint reading group seminar of the CROSSING Special Interest Group on Advanced Cryptography with all interested CROSSING members being invited to participate.

This issue will cover the paper
Micali, Reyzin: “Physically Observable Cryptography” (TCC 2004) (DOI: 10.1007/978-3-540-24638-1_16)
with the following abstract:

„Complexity-theoretic cryptography considers only abstract notions of computation, and hence cannot protect against attacks that exploit the information leakage (via electromagnetic fields, power consumption, etc.) inherent in the physical execution of any cryptographic algorithm. Such “physical observation attacks” bypass the impressive barrier of mathematical security erected so far, and successfully break mathematically impregnable systems. The great practicality and the inherent availability of physical attacks threaten the very relevance of complexity-theoretic security.

To respond to the present crisis, we put forward physically observable cryptography: a powerful, comprehensive, and precise model for defining and delivering cryptographic security against an adversary that has access to information leaked from the physical execution of cryptographic algorithms. Our general model allows for a variety of adversaries. In this paper, however, we focus on the strongest possible adversary, so as to capture what is cryptographically possible in the worst possible, physically observable setting. In particular, we consider an adversary that has full (and indeed adaptive) access to any leaked information; show that some of the basic theorems and intuitions of traditional cryptography no longer hold in a physically observable setting; and construct pseudorandom generators that are provably secure against all physical-observation attacks.

Our model makes it easy to meaningfully restrict the power of our general physically observing adversary. Such restrictions may enable schemes that are more efficient or rely on weaker assumptions, while retaining security against meaningful physical observations attacks.“

Further information about the location

The seminar takes place in a virtual format using BigBlueButton. Please join us using the provided link in your favorite browser. When joining, please select that you want to participate with „microphone“. Then you connect to the server performing an echo-test. If you hear yourself correctly then please choose the option „thumbs-up“. Then you have successfully joined the seminar and you are automatically muted. Please keep this setting to provide everyone a good sound quality unless you have a question. Then you can please unmute yourself and ask a question. This seminar is still meant to be interactive.

Further information