Question

Alice has constructed a document. Bob needs to verify the document's integrity. Which of the following data items must they share? Select all that apply.

Group of answer choices

h) A one-way hash value encrypted with Bob's private key

c) Bob's private key

e) A randomly generated key encrypted with Alice's public key

f) A randomly generated key encrypted with Bob's public key

d) Alice's private key

a) Alice's public key

b) Bob's public key

g) A one-way hash value encrypted with Alice's private key

Answer 1

Alice has constructed a document. Bob needs to verify the document's integrity. Which of the following data items must they share?

Answer:

a) Alice's public key

g) A one-way hash value encrypted with Alice's private key

• When a signature is verified by the public key, it decrypts to a hash matching the message. That hash can only be decrypted using the public key if it were encrypted with the private signing key. Public keys are produced by the key pair owner. Certificate authorities sign the public key's certificate.
• The one-way function, Hash-Based Message Authentication Code with Secure Hashing Algorithm 1 (HMAC-SHA1), is run over the header and payload with a secret key. The sender writes the HMAC-SHA1 hash into the authentication tag, and the receiver runs the same computation and checks its result against the tag.