Lecture 2 : Computational Notion of Security
نویسنده
چکیده
We introduce the notion of computational security, in contrast to the perfect security of last lecture, which was an information-theoretic, rather than computational notion. We review the notions of algorithm running time, assymptotic notation, and polynomial time algorithms. We introduce notions of efficient algorithms, negligible probabilities, and adversarial advantage in attacking a cryptosystem. We exemplify these notions with an example of computational security definition for (private-key) encryption, namely the indistinguishability of encryption.
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