Week 9 & 10: Digital Certificates Flashcards
1
Q
How is Man in Middle attack prevented with Diffie-Hellman?
A
Bob sends signature and certificate along with g^b.
2
Q
What is the point of a digital signature?
A
Verifies authenticity of message with public key
3
Q
What is the difference between a digital signature and a MAC tag?
A
MAC tag is generated using a symmetric key, so it can be regenerated if key is known.
A digital signature is generated using a private key and can be verified with another public key.
4
Q
What is the point of the digital certificate?
A
Verifies the identity of the sender by using a third party.
5
Q
What does a digital certificate validate specifically?
A
- domain validation
- organization validation
- extended validation
6
Q
When can a certificate be revoked?
A
- If expired
- If company is hacked
- If CA is hacked
- If business name is changed
- If company goes out of business
7
Q
What are the methods to check if certificate is revoked?
A
- Download CRL (Certificate Revocation List) and go through it manually
- OCSP - Real time look up by contacting CA and asking it
- OCSP Stapling - Receive latest time stamped OCSP from server
