
1996 = Wassenaar Arrangement  terrorist countries.

Chosen cipherattacks 
 Intruder must capture large portion of cyphertext
 chose which parts are to be decrypted
 translation process is analyzed to identify secret key

How many symmetric keys are required? Formula
N(N+1)/2

PGP 
web of trust between users, users can determine how much they trust one another.

IPSec Provides ...
Integrity, confidentiality, and System authentication. NOT user authentication.

Cesear cipher
 shift in alphabet  key is # of shifts

IPSec  ESP, AH
 ESP = confidentiality, message integrity, and system authentication
 AH = message integrity, and system authentication

Lucifer 
128 bit algorith  accepted as DES  key size went from 128 to 64 and renamed DES

x.509
standard for digital certificates

Concealment cipher 
disguise messages within the text of a body or message, using every other word to form a message

Cryptovariable
another word for key  provides secrecy

Diffie Hillman Algorithm function?
Performs Key exchange

Block ciphers vs. Stream ciphers
 Block ciphers  work better in applications  they work with blocks of data
 Stream ciphers  work better in hardware  work with bits of data

Digital Signature Algorithm (DSA) ? =
Does not perform message encryption or key exchange  the DSS dictates that SHA1 or DSA are to be used for digital signatures

El Gamal
 Asymmectric, (public key algorithm),
 Used for digital signatures,
 encryption,
 key exchange
 calculates discrete logarithms in a finite field.

A good oneway message hashing function ...
creates a message digest from the whole message

Link Encryption 
encrypting header information  ect.

True weakness of DES ...
 key size

Vernam Cipher
 One Time Pad

SHA
 hashing algorithm developed by NASA
 improves upon RC5
 larger hash value of bits .. larger message digest .. more resistent to birthday attacks

Symmetric algorithms are faster becuase ...
they use substitution and transposition

Confusion is carried out by ...
Diffustion is carried out by ...
Confusion is carried out by substitution
Diffustion is carried out by transposition

Key clustering 
One key is used to encrypt two different messages and they both end up with the same cyphertext.

MD2
 128 bit hash algorithm

AES  encryption algorithm?
 Rijndeal

Purpose of public key
 authenticate private key

zero knowledge proof 
you can prove you have a key without sharing private key  don't share too much information

DEA 
algorithm for DES (standard)  16 rounds and 8 parity bits  56 bit true key size

SSL
requires PKI  it performs authentication by using certificate authorities and certificates

HTTPS vs SHTTP
 HTTPS  used to encrypt a channel
 SHTTP  used to encrypted individual messages

Cryptanalysis requires
 Access to ciphertext and algorithm source

SKIP ISAKMP
key management protocols that can be used by IPSec  defacto IKE  internet key exchange  NETWORK LAYER

