Certified Information Security Manager (CISM) — Question 1190

Which of the following is the BEST way to protect against unauthorized access to an encrypted file sent via email?

Answer options

• A. Validating the recipient's identity
• B. Using a digital signature in the email
• C. Utilizing a separate distribution channel for the password
• D. Ensuring a policy exists for encrypting files in transit

Correct answer: C

Explanation

Using a separate distribution channel for the password (option C) ensures that even if the email is intercepted, the password remains secure. Validating the recipient's identity (option A) and using a digital signature (option B) do not directly prevent unauthorized access to the file itself. While having a policy for encrypting files in transit (option D) is important, it does not specifically address the secure sharing of the password needed to access the encrypted file.