8. Cryptography: digital signatures and PKI Flashcards Preview

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Flashcards in 8. Cryptography: digital signatures and PKI Deck (10)
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1
Q

What does a public key certificate consist of?

A
  • Public key - Subject (identity of owner) - Signature binding subject and key by a certificate authority
2
Q

What is the chain of trust?

A

Root CA’s sign certificates for level 1 CA’s, level 1 CA’s sign certificates for level 2 CA’s, etc

3
Q

Whats the definition of existential unforgability?

A
4
Q

Whats the advantages of digitial signatures over message authentication codes? (2)

A
  • Digital signitures are publically verifiable
  • Non-repudiation (whoever signed it can’t say they didn’t)
5
Q

Whats the basic idea for using RSA as a digital signiture?

A

Encrypt (sign) using a secret key, decrypt (verify) using the public key

6
Q

Whats the key generation function for RSA signitures?

A
7
Q

Whats the signing function for RSA signitures?

A
8
Q

Whats the verification function for RSA signitures?

A
9
Q

What is the problem with RSA signitures?

A

Does not provide existential unforgeability

10
Q

How can we add existential unforgeability?

A