How are initialization keys, combination keys and encryption keys generated in Bluetooth?

by Amrita Mitra | Nov 19, 2021 | Bluetooth Security, Exclusive Articles, Featured, Wireless Network And Security

Initialization Key Generation in Bluetooth

Bluetooth uses symmetric key cryptography for authentication and encryption. When two Bluetooth devices pair with each other, they first generate an initialization key. The initialization key is used to generate a combination key in both devices. Once the combination key is derived from the initialization key, the initialization key is discarded.

Please note that the combination key is semi-permanent. When two devices derive a combination key, they can store it and reuse it for multiple sessions.

And, when a master device broadcasts a message to several slave devices, the broadcast message is encrypted using a master key. It is inconvenient for a master device to encrypt a message with several combination keys and send it to different devices.

In this article, we would discuss how the initialization keys, combination keys, and encryption keys are generated in Bluetooth devices using various algorithms.

In this article, we will discuss:

How are initialization keys generated in Bluetooth devices?
How are combination keys generated in Bluetooth devices?
How are encryption keys generated in Bluetooth devices?

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Amrita Mitra

Author

Ms. Amrita Mitra is an author, who has authored the books “Cryptography And Public Key Infrastructure“, “Web Application Vulnerabilities And Prevention“, “A Guide To Cyber Security” and “Phishing: Detection, Analysis And Prevention“. She is also the founder of Asigosec Technologies, the company that owns The Security Buddy.

2 Comments

joao jose dos santos on March 14, 2022 at 6:22 am

e começando agora estou procurando entender obrigado
- Amrita Mitra on March 31, 2022 at 9:34 pm
  
  Thank you.