PDF-Chosen Ciphertext Attacks Against Protocols Based on the RSA Encryption Standard PKCS

Murray Hill NJ 07974 bleichenresearchbelllabscom Abstract This paper introduces a new adaptive chosen ciphertext at tack against certain protocols based on RSA We show that an RSA privatekey operation can be performed if the attacker has access to a. Attacking non-atomic decryption. Online Cryptography Course Dan Boneh. SSH Binary Packet Protocol. Decryption:. s. tep 1: decrypt packet length field only (!). s. Core Concepts. Dr. Kerry A. McKay. 1. Approved for Public Release. Distribution Unlimited 13-1379. All materials is licensed under a Creative Commons . “. Share Alike. ”. license.. http://creativecommons.org/licenses/by-sa/3.0/. Schemes and Parameters. Joppe W. Bos. Microsoft Research. Contains joint work with Kristin . Lauter, . Jake Loftus and Michael Naehrig. Computing on Encrypted Data. Motivation. Outsource data and computation. Cryptanalysis . 2. Block Cipher – Attack Scenarios. Attacks on encryption schemes. Ciphertext only attack. : only ciphertexts are given. Known plaintext attack. : (plaintext, ciphertext) pairs are given. The ROM, FDH, using the ROM. From previous lecture. Ciphers . Stream ciphers : many follow OTP + PRG strategy. Block ciphers : work on plaintext of limited size = block. output ciphertexts of same size. from trapdoor permutations. Public key encryption:. definitions and security. Online Cryptography Course Dan Boneh. Public key encryption. E. D. Alice. Bob. pk. sk. Overview. Encryption technologies. Combining encryption technologies for practice. Using encryption technologies for identification – digital signatures. Public key infrastructure. 2. Introduction. Diffie. -Hellman. The . ElGamal. . Public-key System. Online Cryptography Course Dan Boneh. Recap: public key encryption: . (Gen, E, D). E. D. pk. m. c. c. m. pk. , . sk. pk. c. . . . Enc. pk. (m). m. = . Dec. sk. (c). c. pk. pk. Public-key encryption. A public-key encryption scheme is composed of three PPT algorithms:. Gen: . key-generation algorithm. Slides adopted by Prof. William . Enck. , NCSU. Private-key crypto is like a door lock . Encryption and Message Authenticity . Public Key Crypto (10,000 . ft. view) . Separate keys for encryption and decryption . Public key encryption from Diffie -Hellman The ElGamal Public-key System Online Cryptography Course Dan Boneh Recap: public key encryption: (Gen, E, D) E D Cryptography Lecture 3 So far… “Heuristic” constructions; construct, break, repeat, … Can we prove that some encryption scheme is secure? First need to define what we mean by “secure” in the first place… 1. Recap. Number Theory Basics. Abelian Groups. . for distinct primes p and q.  . 2. RSA Key-Generation. KeyGeneration. (1. n. ). Step 1: Pick two random n-bit primes p and q. . Step 2: Let N=. Student: Q.D. MCGAW. Supervisors: . Dr.. Wei Dai and . Dr.. Cong Ling. Second marker: Professor . Athanassios. . Manikas. 20 June 2016. Provide a general purpose C++ API for homomorphic encryption and cloud computing.