問79
頻出度★★★
WPA2による暗号化を設定したアクセスポイントがある。このアクセスポイントを経由して，図のようにPCをインターネット上のWebサーバに接続するとき，WPA2による暗号化の効果が及ぶ範囲として，適切なものはどれか。 図（ネットワーク構成）: PC ―（無線）― アクセスポイント ―（有線）― ファイアウォール ―（有線）― インターネット ―（有線）― Webサーバ
平成28年度 秋期 ITパスポート試験 問79
This question's explanation and your answers so far.
解説
問 79
- ア
正解 WPA2 is a standard for encrypting the wireless LAN (Wi-Fi) segment, and its encryption only takes effect between the wirelessly connected terminal and the access point. In the figure, only the segment between the PC and the access point is wireless; everything after that — access point → firewall → Internet → Web server — is wired. Therefore, what WPA2 encryption protects is the wireless segment “from the PC to the access point”, so the correct answer is ア.
Incorrectイ
The segment from the access point to the firewall is wired and is outside the scope of WPA2. A firewall is a device that permits or blocks communication, not a device that extends encryption, so the encryption range cannot be widened to cover “from the PC to the firewall”.
Incorrectウ
Encrypting the entire path from the PC to the Web server is the role of a different mechanism such as SSL/TLS (HTTPS) or a VPN. Because WPA2 protects only the wireless segment, it cannot encrypt the whole end-to-end path that includes the wired segments and the Internet.
Incorrectエ
The path from the access point to the Web server is entirely wired and does not include the wireless segment that WPA2 protects. Conversely, the PC that is connected wirelessly is left out of this range, so it does not match the location that WPA2 actually encrypts.
ここがポイント
- WPA2 is a wireless LAN encryption standard, and its encryption only takes effect over the wireless segment between the wireless terminal (PC) and the access point.
- To encrypt the end-to-end path from the PC to the Web server (including the wired segments), a different means such as SSL/TLS (HTTPS) or a VPN is required.
用語