Best Practices for Public Networks
Introduced| English | Meaning |
|---|---|
| exploits/ˈeksplɔɪts/ | Methods or code that take advantage of vulnerabilities to cause unintended or unauthorised behaviour. |
| zero days/ˈzɪərəʊ deɪz/ | Previously unknown vulnerabilities for which defenders have had no advance opportunity to prepare a specific fix. |
| motivation/ˌməʊtɪˈveɪʃn/ | The reasons or influences that encourage a person to act or make an effort. |
| evil twin/ˈiːvl twɪn/ | evil twin |
| access point/ˈækses pɔɪnt/ | A network device or function that connects wireless clients to a network. |
| SSID/ˌes es aɪ ˈdiː/ | The name or identifier used to distinguish a wireless network. |
| jamming/ˈdʒæmɪŋ/ | jamming |
| denial of service/dɪˈnaɪəl ɒv ˈsɜːvɪs/ | An attack that prevents or disrupts legitimate access to a system or service. |
| war driving/wɔː ˈdraɪvɪŋ/ | war driving |
| encrypted/enˈkrɪptɪd/ | Describing data transformed by a cryptographic process so that recovering its meaning requires the appropriate decryption information. |
| virtual private network/ˈvɜːtʃuːəl ˈpraɪvət ˈnetwɜːk/ | virtual private network |
Know your adversary
- Low-skilled attackers buy ready-made tools and reuse known exploits 漏洞利用.
- High-skilled attackers write their own tools and find zero days 零日漏洞.
- Their motivation 动机: greed, revenge, politics, or belief.
Three wireless attacks
- Evil twin 双胞胎恶意热点: a fake access point 接入点 copies the real network name (SSID 服务集标识符).
- Jamming 干扰攻击: a strong signal floods the air — a denial of service (DoS) 拒绝服务.
- War driving 战争驾驶: driving around to detect networks and leaked signal.
An evil twin copies a café's network name so the victim's laptop connects to the attacker
Which wireless attack is it?
An evil twin copies the SSID; jamming floods the air to block access; war driving hunts for networks.
An adversary sets up a fake access point copying the real SSID. This is a(n)...
Difficulty 1/5 · 100 coins + a small bonus on first completion today
Copying the SSID to lure victims is the evil twin.
An undocumented vulnerability that no patch exists for yet is called a...
Difficulty 1/5 · 100 coins + a small bonus on first completion today
A zero day is a brand-new, unpatched hole.
Protecting yourself
- Check the network name exactly matches the one you want.
- Prefer encrypted 加密的 sites (HTTPS) so an evil twin cannot read them.
- Use a virtual private network (VPN) 虚拟专用网络 to encrypt all traffic.
Connecting to free Wi-Fi called "CoffeeShop" does not prove it is the real one. An evil twin copies the name exactly. Verify the network with staff before joining.
On an evil-twin network, HTTPS sites still keep your data encrypted.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
HTTPS encryption protects you even if traffic is intercepted.
A tool that encrypts all your traffic to its operator is a ____.
Difficulty 1/5 · 100 coins + a small bonus on first completion today
A VPN (virtual private network) encrypts your traffic.
Which protect you on public Wi-Fi? (Choose all)
Difficulty 2/5 · 140 coins + a small bonus on first completion today
Turning off your firewall makes you less safe.
You join "Airport_Free_WiFi" and log into your bank. If it was an evil twin, the adversary sees your traffic — but because the bank uses HTTPS, your login stays encrypted and safe. HTTPS is your seatbelt on public Wi-Fi.
Adversaries differ by skill and motivation. On public Wi-Fi, beware the evil twin, jamming, and war driving. Protect yourself by verifying the network name, preferring HTTPS, and using a VPN.