7 Cryptography and the PKI Flashcards
What are the four goals of cryptography?
Confidentiality, integrity, authentication, non-repudiation
What does confidentiality in cryptography refer to?
The use of encryption to protect sensitive information from prying eyes
Define integrity in the context of cryptography.
Ensuring that data is not maliciously or unintentionally altered
What is authentication in cryptography?
Validating the identity of individuals using encryption
Explain non-repudiation in cryptography.
Ensures that individuals can prove to a third party that a message came from its purported sender
What is symmetric encryption?
Uses the same shared secret key to encrypt and decrypt information
What is required for symmetric encryption to function?
A mechanism to exchange shared secret keys
What does the Diffie–Hellman algorithm provide?
An approach to exchange shared secret keys for symmetric encryption
What is asymmetric encryption?
Provides each user with a pair of keys: a public key and a private key
How does asymmetric encryption work?
Anything encrypted with one key can be decrypted with the other key from the pair
How do digital signatures provide non-repudiation?
By allowing a third party to verify the authenticity of a message
What process is followed to create a digital signature?
Using a hash function to generate a message digest and encrypting it with the sender’s private key
How can others verify a digital signature?
Decrypting it with the sender’s public key and comparing the message digest
What is the purpose of digital certificates?
To provide a trusted mechanism for sharing public keys
Who issues digital certificates?
Certificate authorities (CAs)
What role do CAs play in digital certificates?
They apply their digital signature to demonstrate trust in the certificate
What can recipients of a digital certificate rely on?
The public key it contains if they trust the issuing CA
What is Tor’s significance in cryptography?
Uses perfect forward secrecy for anonymous communication over the Internet
What is the blockchain?
An immutable distributed public ledger made possible through the use of cryptography
