More Cyber Security

Front 1

Observe what A and B are communicating

Back 1

Attacks on Confidentiality

Front 2

Observe that A and B ARE communicating/How Much

Back 2

Traffic Analysis

Front 3

Modify Communication between A and B

Back 3

Attacks on Integrity

Front 4

Deny A and B from communicating

Back 4

Denial of Service

Front 5

How are A, B and Adversary usually modeled

Back 5

Probabilistic Polynomial-Time Turing Machines (PPT)

Front 6

Security Parameter

Back 6

Variable Lambda measures the input in a problem

Front 7

A and B effecient communication

Back 7

p(lambda) for some polynomial p

Front 8

lambda

Back 8

key size, bigger is better

Front 9

Adversary's Probability of breaking security

Back 9

Directly proportional to SP (lambda) size.

Front 10

Negligible Probability

Back 10

A function is negligble if for every positve polynomial p there exists an N such that all lambda is greater than n. Example function v(lambda)<(1/p(lamda))

Front 11

One-Way Function

Back 11

easy to compute on every input but hard to invert given the image of a random input.

Front 12

Collection of one-way functions

Back 12

a set, each function has a domain and range.

Front 13

Trapdoor one-way Function

Back 13

Hard to invert unless the trapdoor is known. Can be inverted effeciently with the trapdoor but otherwise the function is one way

Front 14

applications of one-way functions

Back 14

make a public identifier for private info, include a digital signature with a trap door

Front 15

Factors for deciding p, n, and lambda size

Back 15

Life Span: How long the info must be protected. Security Margin: Computational power of attacker. Cryptanalysis: The progress of cryptography and hacking in the future.

Front 16

Digital Signature

Back 16

a DS scheme is a trip (G,S,V) of effeciently computable algorithms. G outputs a public key K and a private key K-1. S takes a message m and the key as an input and outputs a signature. V takes message m, the signature and public key as input and outputs a bit b. If the signature with m connects to the bits its valid.

Front 17

Types of attacks against Digital Signature Schemes

Back 17

Key Only Attack, Known Signature Attack, Chosen Message attack. All rely on knowing the public key obviously.

Front 18

Pseudorandom Functions

Back 18

Looks like a random function to anyone not knowing the key(first input) make good MAC, message authentication code shemes

Front 19

Message Authentication Code

Back 19

Creating MAC's rom only hash functions is desirable.

Front 20

HMAC

Back 20

Some confusing ass function

Front 21

Cryptogaphic hash function

Back 21

hash function that takes an arbitrary block of data and returns a fixed-size bit string - the cryptographic hash value such that any change to the data will change the hash value.