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Crypto Bro Rigby. History

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Presentation on theme: "Crypto Bro Rigby. History"— Presentation transcript:

1 Crypto Bro Rigby

2 History http://en.wikipedia.org/wiki/Cryptography#History_of_cryptography_and_cryptanalysis

3 Terms Plaintext Encryption Cipher Cipher text Cryptography Cryptographers

4 Terms Cryptanalysis Cryptanalysts Cryptology Keys Keyspace Hashing

5 Symmetric Encryption (Single Key)

6 How big are keys? 128? Has 2 128 possible values – The total lifetime of the universe is about 2 61 seconds. – Number of atoms in the earth 2 170 – Number of atoms in the sun 2 190 – Number of atoms in the universe 2 265

7 Algorithms' Stream Ciphers (1 bit at a time) Block Ciphers (Chunks at a time, AES uses 128 bit blocks) Examples – DES, 3DES (No Longer Used) – Twofish, Serpent, AES, Blowfish, CAST5, RC4, TDES, IDEA

8 Symmetric Encryption DES (Data Encryption Standard) – 56 Bit – Federal Information Processing Standard (FIPS 46) in 1976 – 1997: RSA contest won by distributed crack (10,000 clients) – 1998: EFF built a $250K machine to crack DES in 2 days 2002 AES (May 26 th, 2002) – 5 Finalists (Mars,RC6,Rijndael,Serpent,Twofish) – 128, 192, 256 bit keys. – The largest successful publicly-known brute force attack has been against a 64-bit RC5 key by distributed.net (http://en.wikipedia.org/wiki/Advanced_Encryption_Standard)

9 Symmetric Encryption 128-bit encryption – 3 x 10 38 – 1 modern computer needs 10 24 years to crack 128-bit – 1 billion modern computers need 10 15 years to crack – 1 billion modern computers need 10 53 years to crack 256-bit – Some other cracking method required Other avenues are far easier: – Spyware/Rootkits – Social Engineering – Phishing – Password cracking Reference (The Struggle Between Unbreakable Encryption and Stupid Passwords By Brian Basgen bbasgen@pima.edu)

10 Asymmetric Encryption 2-key

11 Asymmetric Algorithms’ Diffie-Hellman DSS ElGamal – Based off of Diffie-Hellman RSA Cramer-Shoup

12 XOR Secret Splitting Secret Sharing

13 Hashing Digital Fingerprint – MD5 – SHA-1 Algorithm Output size (bits) Internal state size (bits) Block size (bits) Max message size (bits) Word size (bits) RoundsOperationsCollision SHA-0160 5122 64 − 13280 +,and,or,xor, rotfl Yes SHA-1160 5122 64 − 13280 +,and,or,xor, rotfl 2 63 attack SHA- 256/224 256/2242565122 64 − 13264 +,and,or,xor, shr,rotfr None yet SHA- 512/384 512/38451210242 128 − 16480 +,and,or,xor, shr,rotfr None yet http://en.wikipedia.org/wiki/Sha1

14 Digital Signatures Signing uses Private Key Verifying uses Public Key “Authentication” of message. Hash Message. Sign Hash. Send message with Encrypted Hash. Receiver decrypts hash with public key and then matches hash sent with hash of message.

15 PKI

16 Digital Certificates Binds a name to a public key. X.509 Standard Registration with CA – Software, hardware, procedures, policies, people – RA Responsible for verification – Class 1 – Email – Class 2 – Software signing – Class 3 – Be own CA

17 Digital Certificates Key Pair Generation Cert creation Cert distribution Key backup and recovery


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