Reading the Crypto Classics

Rogaway: „Formalising Human Ignorance“ (VIETCRYPT 2006)

2023/02/21 10:00-12:00

Moderator: Jérôme Govinden (TU Darmstadt, Cryptography and Network Security Group) | Location: online

Organizer: , TU Darmstadt, Cryptography and Information Security Group


This talk is the fourth session in the seminar series “Reading the Crypto Classics” for the winter term 2022/23. 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/talk

Rogaway: „Formalising Human Ignorance“ (VIETCRYPT 2006) available at

with the following abstract:

“There is a rarely mentioned foundational problem involving collision-resistant hash-functions: common constructions are keyless, but formal definitions are keyed. The discrepancy stems from the fact that a function H : {0,1}* → {0,1}n always admits an efficient collision-finding algorithm, it’s just that us human beings might be unable to write the program down. We explain a simple way to sidestep this difficulty that avoids having to key our hash functions. The idea is to state theorems in a way that prescribes an explicitly-given reduction, normally a black-box one. We illustrate this approach using well-known examples involving digital signatures, pseudorandom functions, and the Merkle-Damgård construction.”


For participation in this virtual format, please write an e-mail to the organizer (see above).

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