'Online cryptography' presentation slideshows

Trusted 3 rd parties

Online Cryptography Course Dan Boneh. Basic key exchange. Trusted 3 rd parties. K ey management. Problem: n users. Storing mutual secret keys is difficult Total: O(n) keys per user. A better solution. Online Trusted 3 rd Party (TTP). TTP.

492 views • 36 slides

The data encryption standard (DES)

Online Cryptography Course Dan Boneh. Block ciphers. The data encryption standard (DES). Block ciphers: crypto work horse. n bits. n bits. E, D. PT Block. CT Block. Key. k Bits. Canonical examples: 3DES: n= 64 bits, k = 168 bits

525 views • 16 slides

The One Time Pad

267 views • 14 slides

PRG Security D efs

230 views • 13 slides

Public-key encryption

Online Cryptography Course Dan Boneh. Basic key exchange. Public-key encryption. Establishing a shared secret. Goal : Alice and Bob want shared secret, unknown to eavesdropper For now: security against eavesdropping only (no tampering). Alice.

247 views • 11 slides

The RSA trapdoor permutation

Online Cryptography Course Dan Boneh. Public Key Encryption from trapdoor permutations. The RSA trapdoor permutation. Review: trapdoor permutations. Three algorithms: (G, F, F -1 )

314 views • 10 slides

Modes of operation: one time key

250 views • 10 slides

What is cryptography?

Online Cryptography Course Dan Boneh. Introduction. What is cryptography?. Crypto core. Talking to Alice. Talking to Bob. Secret key establishment: Secure communication:. Alice. Bob. a ttacker???. m 1. k. k. m 2. c onfidentiality and integrity.

224 views • 9 slides

Constructions

Online Cryptography Course Dan Boneh. Public Key Encryption from trapdoor permutations. Constructions. Goal: construct chosen- ciphertext secure public-key encryption. Trapdoor functions (TDF).

219 views • 8 slides

Stream ciphers are semantically secure

Online Cryptography Course Dan Boneh. Stream ciphers. Stream ciphers are semantically secure. Goal: secure PRG ? semantically secure stream cipher. Stream ciphers are semantically secure.

221 views • 7 slides

Merkle Puzzles

Online Cryptography Course Dan Boneh. Basic key exchange. Merkle Puzzles. Key exchange without an online TTP?. Goal : Alice and Bob want shared key, unknown to eavesdropper For now: security against eavesdropping only (no tampering). Alice.

548 views • 7 slides

A Unifying Theme

Online Cryptography Course Dan Boneh. Public key encryption from Diffie -Hellman. A Unifying Theme. O ne-way functions (informal). A function f: X ? Y is one-way if There is an efficient algorithm to evaluate f(?), but

240 views • 7 slides

Arithmetic algorithms

Online Cryptography Course Dan Boneh. Intro. Number T heory. Arithmetic algorithms. Representing bignums. Representing an n-bit integer (e.g. n =2048) on a 64-bit machine

229 views • 7 slides

The Merkle-Damgard Paradigm

Online Cryptography Course Dan Boneh. Collision resistance. The Merkle-Damgard Paradigm. Collision resistance: review. Let H: M ?T be a hash function ( | M| >> |T | ) A collision for H is a pair m 0 , m 1 ? M such that:

151 views • 6 slides

Is RSA a one-way function?

Online Cryptography Course Dan Boneh. Public Key Encryption from trapdoor permutations. Is RSA a one-way function?. Is RSA a one-way permutation?. To invert the RSA one-way func . (without d ) attacker must compute: x from c = x e (mod N).

203 views • 6 slides

Farewell (for now)

Online Cryptography Course Dan Boneh. Farewell (for now). Quick Review: primitives. CTR. PRG. PRF, PRP. MAC. CMAC, HMAC PMAC. GGM. Collision resistance. k ey exchange. Diffie -Hellman groups. Trapdoor Functions. p ublic key encryption.

243 views • 6 slides