On a public-key cryptosystem when there is no previous knowledge between parties, which of the following will BEST help to prevent one person from using a fictitious key to impersonate someone else?
On a public-key cryptosystem when there is no previous knowledge between parties, which of the following will BEST help to prevent one person from using a fictitious key to impersonate someone else?
In a public-key cryptosystem, when there is no previous knowledge between parties, sending a certificate that can be verified by a certification authority with the public key is the best method to prevent impersonation. Certificates bind a public key to a specific entity, and the certification authority's verification ensures the authenticity of the key. This establishes trust and prevents unauthorized individuals from using fictitious keys to impersonate legitimate parties.
Answer: A Since there is no previous connection, the initial link must be established via CA.
A. Send a certificate that can be verified by a certification authority with the public key. Sending a certificate that can be verified by a certification authority with the public key would be the best approach to prevent one person from using a fictitious key to impersonate someone else in a public-key cryptosystem. Certificates are used to bind a public key to a specific entity, and a certification authority's verification helps ensure the authenticity of the key. This approach establishes trust and prevents unauthorized individuals from using fake keys to impersonate legitimate parties.
A, Sending a certificate that can be verified by a certification authority (CA) with the public key helps establish trust and authenticity.
only the recipient could decrypt the message and get the sender's public key. Using the sender's public key, the recipient can reply the message under the same mechnism.
Answer: A
Option B does not verify the authenticity of the sender's public key, leaving the risk that someone using a forged key could send a message, thus requiring the use of certificates from a Certification Authority.