PPT-Defining Public Key Encryption

Slides by Prof Jonathan Katz Lightly edited by me Review privatekey setting Two or more parties who wish to securely communicate share a uniform secret key k in advance Same key k used for sending or receiving. 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). Name : . Maryam Mohammed . Alshami. ID:. H00204657. Encryption. : . is the process of encoding messages or information in such a way that only authorized parties can read it. .. Important part of computing to keep our file . in the . B. ounded-. R. etrieval . M. odel. Joël. Alwen, . Yevgeniy. . Dodis. , . Moni. . Naor. , Gil . Segev. , . Shabsi. . Walfish. , Daniel . Wichs. . Speaker: Daniel . Wichs. 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?. 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. 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 : . bosco. If this data was stored in a database, it might look like:. Is Encryption Safe?. Yes, Encryption is safe. The amount of time, energy and cost to crack most modern cryptographic technologies makes the act of attempting to decrypt encrypted code an expensive task that is, virtually speaking, inevitable. Although encryption does have vulnerabilities that rest largely outside of the power of the technology. Meaning if you give someone a USB with the key or tell them it.. Cryptography. Is:. A tremendous tool. The basis for many security mechanisms. Is not:. The solution to all security problems. Reliable unless implemented and used properly. Something you should try to invent yourself. 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. Dana . Dachman. -Soled. University of Maryland. Deniable Public Key Encryption. [Canetti, . Dwork. , . Naor. , . Ostrovsky. , 97]. Sender. Receiver.  .  . s.  . For any . in the message space, can produce a . Symmetric . Key Distribution Using Asymmetric Encryption . Distribution . of Public Keys. Key Management and Distribution. Symmetric Key Distribution Using Symmetric Encryption. For symmetric encryption to work, the two parties to an exchange must . Techniques . Symmetric Cipher Model. Basic terminology:. Plaintext:. original message to be encrypted. Cipher text: . the encrypted message. Enciphering or encryption Algorithm: . The process of converting plaintext into cipher text..