問74
頻出度★★★
無線 LAN の暗号化方式であり, WEP では短い時間で暗号が解読されてしまう問題が報告されたことから, より暗号強度を高めるために利用が推奨されているものはどれか。
平成31年度 春期 ITパスポート試験 問74
テクノロジ系ネットワーク › ネットワーク方式
This question's explanation and your answers so far.
解説
問 74
Incorrectア
ESSID is a network name (identifier) used to identify a wireless LAN access point; it is not a method for encrypting communication and has nothing to do with encryption strength.
Incorrectイ
HTTPS is a mechanism that encrypts web communication (HTTP) with SSL/TLS, and its target is the communication between browser and server. It is not an encryption method for the wireless LAN segment itself, so it is incorrect.
Incorrectウ
S/MIME is a method for encrypting and digitally signing email, and its target is email. It is not a wireless LAN encryption method, so it is incorrect.
- エ
正解 “エ WPA2” is the correct answer. WEP was an early encryption method for wireless LANs, but its key length was short and its encryption algorithm (RC4) also had implementation weaknesses, so it was reported to be crackable in a short time. The successor standard that addresses this weakness is WPA, and the one that further adopts the stronger encryption algorithm AES (CCMP) to raise encryption strength is WPA2. Therefore, the wireless LAN encryption method recommended for use in place of WEP is WPA2.
ここがポイント
- Wireless LAN encryption methods have been strengthened in the order WEP → WPA → WPA2 (→ WPA3). WEP is vulnerable, and WPA2 or later is now recommended.
- Distinguish that ESSID (network identifier), HTTPS (encryption of web communication), and S/MIME (encryption of email) all differ in purpose and target from “encryption of the wireless LAN segment.”
用語