ITPEC FE Morning October 2021 Question 38
A typical example of security threats is information leakage when a sender sends data containing important information to a receiver. Which of the following is the most appropriate measure to prevent information leakage?
Explanation
Encrypt with the receiver's public key, decrypt with the receiver's private key — the key needed to read the data never travels.
The receiver creates the key pair and sends only the public key, which is safe to disclose. Data encrypted with it can be decrypted only with the matching private key, which stays with the receiver. Someone who intercepts the email or the public key still cannot read the data.
Answer (c)
Why not others:
- •(a) — the decryption key is sent by email, the same channel as the data, so anyone who intercepts both emails can decrypt; a private key should never leave its owner
- •(b) — the password is in the same email as the locked file, so whoever gets the email gets both; checking the address prevents misdelivery but not interception
- •(d) — compression saves space but does not protect the data, and a lost USB memory can be read by anyone
Key rule: Never send a decryption key along the channel it protects; with public key cryptography the receiver publishes the public key and keeps the private key.
Security · AI-written, may contain errors
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