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.
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.
Answer: A
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.
A, Sending a certificate that can be verified by a certification authority (CA) with the public key helps establish trust and authenticity.