WPA Shared key
A single, secret value that is known and utilized by several parties, usually the sender and the recipient, is referred to as a “shared key” in network security and cryptography. Another name for this technique is symmetric-key cryptography.
A shared key is a secret password, passphrase, random string, or code that is used by communication devices to accomplish data encryption and authentication.
Core Function in Symmetric Cryptography
The symmetry of the shared key system in cryptography refers to the use of the same key on both ends of the connection.
- Encryption: The sender converts the plaintext message into unintelligible ciphertext by using the shared key.
- Decryption: The recipient restores the ciphertext to its original, readable state using the same key.
The majority of data in most secure communications is encrypted using shared key methods (such as Advanced Encryption Standard(AES), DES, or 3DES) because of their speed and effectiveness.
Shared Key Contexts and Examples
Many networking and security applications make use of the shared key concept:
Wireless Security (PSK)
The most common name for the shared key in wireless networking is a Pre-Shared Key (PSK).
- The WPA/WPA2 Personal (PSK) mode is designed for small office or home networks (SOHO). Before clients may connect to the WLAN, the Access Point (AP) and each client device must have the same key string, or passphrase, known as the PSK, configured and shared.
- Key Protection: The PSK is never transmitted over the air and is kept private. Rather, it is employed in a procedure known as the four-way handshake to generate and communicate encryption key material (via TKIP or AES/CCMP).
- Security Evolution: Weak shared-key security was employed by earlier techniques such as Wired Equivalent Privacy (WEP). During the four-way handshake, dictionary attack vulnerabilities were present in WPA/WPA2-Personal modes. In order to avoid the PSK from being revealed, WPA3-Personal uses Simultaneous Authentication of Equals (SAE).
- Contrast with Enterprise: WPA/WPA2 Enterprise mode uses 802.1X/EAP authentication rather than a pre-shared key.
Also Read About WPA Wi Fi Protected Access Definition And Features of WPA
Network Encryption and VPNs
The terms session key and shared session key can also be used to refer to the shared key in the context of IPsec VPNs and encryption.
- IPsec Authentication: During IPsec Phase 1 negotiation, PSK is one technique used to confirm the identification of peer Virtual Private Network (VPN) equipment.
- Key Establishment: Asymmetrical algorithms, such as Diffie-Hellman (DH) Key Exchange, are frequently employed especially to enable two devices to safely establish this shared secret keying material (symmetrical keys) across an untrusted network, even though symmetrical techniques necessitate a shared key.
Integrity and Authentication
- A shared secret key is used by Hashed Message Authentication Code (HMAC) algorithms like MD5 and SHA-1 to ensure that a message is legitimate and intact and hasn’t been tampered with. For instance, a 128-bit shared secret key is used by Message Digest 5 Algorithm MD5.
- EAP-FAST: The Protected Access Credential (PAC), a type of shared secret produced by the Authentication Server, is used in this enterprise authentication technique.
Advantages and Limitations of Shared key
Despite the substantial security dangers, the speed and ease of use of a shared key system are the main reasons for its adoption.
| Feature | Description |
|---|---|
| Advantages | Speed and Efficiency: It is very fast and efficient, particularly for encrypting large amounts of data. |
| Simplicity: It is simple to set up and configure without needing specialized servers, working well for home or small networks. | |
| Limitations | Key Exchange Challenge: The biggest challenge is the need to securely exchange the key between the sender and receiver beforehand, as both must possess it. |
| Security Risk: The entire communication relies on the secrecy of the single shared key. If the key is compromised, leaked, or guessed, the entire network or communication is exposed. | |
| Scalability Issues: It is poor for large networks because secure communication requires a unique shared key for every pair of users. For N people, N(N-1)/2 keys are required. |
Comparison to Asymmetric Cryptography
Symmetric shared key systems encrypt and decode data with a single key. Asymmetric (Public/Private Key) cryptography, which employs two separate keys a public key for encryption and a private key for decryption, differs significantly from this.
Contemporary secure protocols, such as TLS/SSL for HTTPS, frequently employ a hybrid strategy: they securely exchange a shared key using slower public-key cryptography before transferring the majority of the data using the faster shared key (symmetric).