Four-way handshake is a crucial process used in computer networks to establish a secure connection between devices, typically in wireless networks. It ensures that both the client (e.g., a device like a laptop or smartphone) and the access point (e.g., a Wi-Fi router) have the correct credentials for secure communication. This handshake protocol plays a fundamental role in preventing unauthorized access and securing data transmission over the network.
The history of the origin of Four-way handshake and the first mention of it.
The concept of the Four-way handshake was first introduced in the 802.11i amendment to the IEEE 802.11 standard, which defines the security mechanisms for Wi-Fi networks. The IEEE 802.11i amendment was published in 2004 to address the security vulnerabilities present in the earlier WEP (Wired Equivalent Privacy) and WPA (Wi-Fi Protected Access) protocols.
Detailed information about Four-way handshake. Expanding the topic Four-way handshake.
The Four-way handshake is an integral part of the WPA2 (Wi-Fi Protected Access 2) security protocol, which is widely used to secure Wi-Fi networks today. It is designed to establish a secure connection between a client device and an access point in a step-by-step manner, ensuring that both parties possess the correct encryption keys before data transmission begins.
The internal structure of the Four-way handshake. How the Four-way handshake works.
The Four-way handshake involves four messages exchanged between the client and the access point:
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Message 1 – Request (M1): The client initiates the handshake by sending a request to the access point, indicating its intention to join the network.
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Message 2 – Response (M2): In response to the client’s request, the access point sends a message containing important information, including its nonce (random number) and the group key.
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Message 3 – Request (M3): The client responds to the access point by sending another request, including its nonce and additional data encrypted using the Pairwise Transient Key (PTK), derived from the pre-shared key (PSK) and the nonces.
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Message 4 – Response (M4): The access point acknowledges the client’s request by sending its final message, which contains the nonce and additional data encrypted using the PTK.
After this exchange, both the client and the access point have verified each other’s credentials, and the PTK is established. This key is now used to encrypt the data transmitted between the two parties, ensuring a secure communication channel.
Analysis of the key features of Four-way handshake.
The Four-way handshake provides several essential features for secure communication:
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Mutual Authentication: Both the client and the access point verify each other’s identity and credentials during the handshake process.
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Dynamic Key Generation: The handshake generates a unique PTK for each client-access point pair, making it difficult for attackers to decrypt the communication even if they capture the handshake messages.
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Fresh Nonces: Nonces used in the handshake are random and unique for each session, preventing replay attacks.
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Forward Secrecy: The PTK used to encrypt the data is not derived from the PSK directly but from the nonces exchanged during the handshake. This property ensures that compromising one PTK does not compromise past or future communications.
Write what types of Four-way handshake exist. Use tables and lists to write.
There is typically only one type of Four-way handshake, which is used in WPA2-PSK (Pre-Shared Key) networks. However, depending on the encryption protocol used in the network, the way the keys are derived may differ slightly.
Types of Four-way handshake:
- WPA2-PSK: Used in home and small office networks, where a pre-shared key (password) is used for authentication.
- WPA2-Enterprise: Used in larger organizations, where an authentication server (e.g., RADIUS) handles the authentication process.
Ways to use Four-way handshake:
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Securing Wi-Fi Networks: The primary purpose of the Four-way handshake is to establish secure connections between clients and access points in Wi-Fi networks.
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Security for IoT Devices: Four-way handshake can also be adapted for securing communication between Internet of Things (IoT) devices and access points, ensuring data integrity and confidentiality.
Problems and Solutions:
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Dictionary Attacks: Attackers can attempt to crack the Wi-Fi password by brute-forcing the PSK. To mitigate this, users should choose strong, complex passwords that are resistant to dictionary attacks.
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WPA2 Vulnerabilities: While WPA2 is generally secure, there have been vulnerabilities in the past (e.g., KRACK attack) that could exploit weaknesses in the handshake. Regular firmware updates for access points and client devices are crucial to patching such vulnerabilities.
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Replay Attacks: Attackers may attempt to capture and replay the handshake messages to gain unauthorized access. The use of fresh nonces and proper implementation of cryptographic algorithms helps prevent replay attacks.
Main characteristics and other comparisons with similar terms in the form of tables and lists.
| Characteristic | Four-way Handshake | Three-way Handshake | Two-way Handshake |
|---|---|---|---|
| Number of Messages Exchanged | 4 | 3 | 2 |
| Mutual Authentication | Yes | Yes | No |
| Dynamic Key Generation | Yes | No | No |
| Common Use Case | Wi-Fi Security | TCP Connection | Simple Messaging |
The Four-way handshake, as a fundamental security mechanism for Wi-Fi networks, will continue to be a critical component of future wireless communication technologies. However, advancements in encryption algorithms and authentication methods will likely be incorporated to strengthen the security of the handshake and make it more resilient to emerging threats.
How proxy servers can be used or associated with Four-way handshake.
Proxy servers act as intermediaries between clients and servers, providing additional layers of security and privacy. While proxy servers do not directly influence the Four-way handshake process between clients and access points in Wi-Fi networks, they can be used in conjunction with the handshake to enhance security in various ways:
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Encrypted Data Transmission: Proxy servers can encrypt data transmitted between the client and the server, complementing the encryption provided by the Four-way handshake.
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Anonymity and Privacy: Proxy servers can hide the client’s IP address from the access point or server, enhancing anonymity and privacy during communication.
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Traffic Filtering: Proxy servers can filter and block malicious traffic, adding an extra security layer to prevent potential attacks.
Related links
For more information about Four-way handshake and network security, you can refer to the following resources:
Remember that understanding the Four-way handshake is crucial for anyone dealing with network security, and implementing it correctly ensures the confidentiality and integrity of data transmitted over Wi-Fi networks.
