Uses of cryptography

What is cryptography used for?

Digital signatures: Anonymous communication
Anonymous digital cash
Election
Private auctions
zero knowledge proof: is a way for the prover to prove to someone to know something whithout revealing any information about that thing itself

Privacy:
- Concerned with concealing the meaning of a message from unintended participants to a communication medium
- Solved with symmetric key block ciphers
- Recipient does not know if the message is intact
- Output of a cipher is ciphertext
Integrity:
- Concerned with the correctness of message in transit
- Assumes there is no active adversery
- Solved with one-way hash functions
- Output of a hash is a message digest
Authentication:
- Concerned with the correctness of a message in transit
- Assumes there are active adversaries
- Solved with Message authentication functions(MAC)
- Output of a MAC is a message tag
Nonrepudiation:
- Concerned with binding transaction
- Goal is to prevent a party from refuting taking party to a transaction
- Solved with public key digital signatures
- Output of a signature algorithm is a signature