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Lecture 7 : CPA Security , MACs , OWFs Lecturer : Daniel Wichs Scribe : Eysa Lee 1 Topic Covered
| Content Provider | Semantic Scholar |
|---|---|
| Author | Wichs, Daniel Lee, Eysa |
| Copyright Year | 2017 |
| Abstract | Recall last lecture we introduced a new notion of security, chosen plaintext attack (CPA). In this model, the adversary is allowed a polynomial number of plaintext queries to an oracle, and the oracle replies with the encryption of these messages. In a challenge phase, the adversary sends two messages m0,m1 and receives an encryption of one of the messages. The adversary is allowed polynomial many more oracle encryption queries, but is finally challenged to identify which of the two messages was encrypted. We can formally define CPA security using CPA-Game, where b ∈ {0, 1}. CPA-Game is defined as follows: 1. The challenger chooses a key k ← {0, 1} 2. The adversary repeatedly chooses messages mi and the challenger sends back ciphertexts ci = Enc(k,mi). The adversary can do this as many times as it wants. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://www.ccs.neu.edu/home/wichs/class/crypto-fall17/lecture7.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
