Cyptography and Society Flashcards
What is modern cryptography
the study of mathematical techniques for security digital information, systems and distributed computations against adversarial attacks
What is Casesars cipher
one of the oldest recorded ciphers, does this by shifting letters backwards and forwards
What is security by obscurity
improving security by keeping the algorithm secret
Define Kerchoffs’ principle
the cypher method must not be required to be secret, and it must be able to fall into the hands of the enemy without inconvenience
Define the sufficient key-space principle
any secure encryption scheme must have a key space that is sufficiently large to make an exhaustive-search attract infeasible
What is the mono-alphabetic substitution cipher
it defines a map from each letter to some letter of the alphabet, where the map is arbitrary, instead of a fixed shift
What can cryptography be
symmetric or asymmetric
What is the key distribution problem
if the key is compromised they would have to create a new one again, it is overall slow and not scalable; how are they going to stop the spread of the keys
What is asymmetric cryptography
There is a public key and private key, they share the public key to encrypt it and the only way to decrypt is via the private key
What is a way a message can be encrypted via asymmetric cryptography
RSA
How is asymmetric cryptography different to symmetric
it has authentication, integrity and accountability (non-repudiation
What is a digital certificate
A certificate authority can issue a digital certificate to prove the ownership of a public key
What does cryptography rely on
the lack of an efficient factorization algorithm
How can attack cryptography
Buteforce (e.g. try all combinations, side channel attack
differential cryptanalysis)
What were the issues with the heartbleed bug
it would bring up previous requests and therefore private information, as it would request more data and it would provide data from memory of previous users
