Encryption+and+Cryptography

__ Certificates __ are used to authenticate. We __authenticate__ in order to protect __confidentiality__. SHA1- hashes MD5 –“ “Hashes are numerical code that encrypts data. Public Key Encryption scrabbles the algorithm with RSA. It is a key. We limit access by authenticating our users. For authentication we need technologies such as  o Hardware: server o Software: Public Key Infastructure (PKI), DES o Information : Keys/Certificates

The strongest way to send a message is with “code”. Code is a method to transform a message into an obscure form. It takes plaintext and substitutes it with other characters/symbols. The problem is that the code has to be shared.

Plaintext in computer is covered by ASCII (each character = 1 byte)

Cipher - transformations of plaintext.A cipher is a an algorithm for performing encryption or decryption. __Mathematical__ · Symmetric key ciphers. Can be hacked by brute force attacks. To make is safe, make it a long number. Good for stored information. o __EX: Data Encryption Standard (DES)__ – 56 bits, Bowfish, AES (128 and 256)

· __Asymmetric Key__ – 2 keys (1 is public and 1 is private). They are nonreversable. The public key only to enrypt. ( 1 way) The private key decrypts the data. Protect the private key!!!!

Protect transmitted data Authenticate – digital signature

**Cracking of the Key**

Bruce Schneier – Implementation PGP example: PKI needs 2 prime #s