Joe Is Exchanging Encrypted Email with Another Party

question 622

Multiple Choice

Joe is exchanging encrypted email with another party. Joe encrypts the initial email with a key. When Joe receives a response, he is unable to decrypt the response with the same key he used initially. Which of the following would explain the situation?

• A) An ephemeral key was used for one of the messages
• B) A stream cipher was used for the initial email; a block cipher was used for the reply
• C) Out-of-band key exchange has taken place
• D) Asymmetric encryption is being used

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Definitions:

Crowdsourcing

The practice of obtaining services, ideas, or content by soliciting contributions from a large group of people, especially from an online community.

Social Networking

The use of internet-based platforms and technologies to build, engage, and share content, ideas, and interests with others in virtual communities and networks.

Digital Divide

The discrepancy between those who have access to the opportunities and knowledge that computers and the Internet offer and those who do not.

Technology

The application of scientific knowledge for practical purposes, especially in industry.