PPT-Authenticated Encryption

Chosen ciphertext attacks Online Cryptography Course Dan Boneh Example chosen ciphertext attacks A dversary has ciphertext c that it wants to decrypt. Attacking non-atomic decryption. Online Cryptography Course Dan Boneh. SSH Binary Packet Protocol. Decryption:. s. tep 1: decrypt packet length field only (!). s. prOtection. (AERO). mcgrew@cisco.com. AERO. Authenticated Encryption algorithm. Stateful. and self-synchronizing. Easy to use. Robust against nonce misuse and decryption misuse. Saves bandwidth. No nonce, no sequence number. CSE 5351: Introduction to Cryptography. Reading assignment:. Chapter 2. Chapter 3 (sections 3.1-3.4). You may skip proofs, but are encouraged to read some of them.. 2. Computational Difficulty (One-Way Functions). How To Secure My Data. . What . to Protect???. DATA. Data At Rest. Data at Rest Examples. Worst Culprits?. Lost. Infected Easily. Used as ‘Backup’. Lent to others. Data Corruptions more common. “Encryption . and . Globalization. ” – China & India. Draft: . . Adoption of . Crypto, the Cloud, and Lawful Access - Peru. “Going . Dark vs. the Golden Age of . Surveillance”. Where you are. 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. usna. . si110. Symmetric Encryption Limitations. Symmetric encryption algorithms use the . same key for encryption and decryption. Both parties must agree to a secret key. Fundamental limitation. How do you exchange a secret key?. Constructions from ciphers and MACs. Online Cryptography Course Dan Boneh. … but first, some history. Authenticated Encryption (AE): introduced in . 2000 . Chris Edwards. IT Services. “All . confidential data . must . be encrypted where stored on a mobile . device” . Mobile Device Encryption Policy. What do we mean by “encrypted” ??. Password Protected. Rainbows (a.k.a. Spectrums). Public Private Key Encryption. HTTPS. Encryption. String Encryption. You have an account on . facebook. , LinkedIn, YouTube etc. . Your login: . costanza@seinfeld.com. Your password is : . Rainbows (a.k.a. Spectrums). Public Private Key Encryption. HTTPS. Encryption. String Encryption. You have an account on . facebook. , LinkedIn, YouTube etc. . Your login: . costanza@seinfeld.com. Your password is : . Last time I promise. Unitary notation . Writing numbers only using 1. 1 -> 1. 2- > 11 . 3 -> 111. (n times). is shorthand for writing n in unitary.  . Family of games. Generalization of section 7.8 in the book (page 278). Authenticated Encryption and Cryptographic Network Protocols David Brumley dbrumley@cmu.edu Carnegie Mellon University Some Straw Men 2 TCP/IP (highly abstracted) packet Destination Machine TCP/IP Stack Cryptography Lecture 9 Arpita Patra © Arpita Patra Recall Attack on cpa -secure scheme from PRF >> cpa -security to cca -security Definitions- cma , scma , cmva , scmva >> MAC