Difference between Bluetooth classic Secure Simple Pairing (SSP) and BLE Pairing/Bonding

[ViBe_4457111]

Hello,

I am using Bluetooth + BLE dual mode stack.

I have gone through Bluetooth SIG Core_4.2 standards. I was going through BLE legacy and Secure connection. Also I was going through Bluetooth SSP (Secure Simple Pairing) for better understanding and comparison.

Below is my understanding.

1) BLE Secure connection is similar to Bluetooth SSP with respect to Public & Private keys exchange.

2) LTK is used in BLE Secure Connection. Link key is used in Bluetooth SSP.

I have few queries. I am bit confused. Whether below statements are correct ? Please correct me if I am wrong.

1) Pairing & Bonding is only in BLE. In BLE pairing keys are not stored whereas in BLE bonding keys are stored.

2) In Bluetooth classic, as part of SSP, Link keys are stored. In Bluetooth there is no Pairing similar to BLE where keys are not stored.

3) Bonding in BLE is similar to Bluetooth classic Pairing with respect to keys storing.

Thanks & Regards

Vishnu Beema

[DheerajPK_41 · Accepted solution]

Hi vibe_4457111

Understanding is correct.

In-order to create a secure and authenticated connection, pairing and bonding are needed in both classic BT as well as BLE.

The purpose of bonding is to create a relation between two Bluetooth devices based on a common link key (a bond). The link key is created and exchanged (pairing) during the bonding procedure and is expected to be stored by both Bluetooth devices, to be used for future authentication.

My suggestion is to use below resources to learn Bluetooth basics.

1. google.com
2. https://www.bluetooth.com/blog/ (Eg: https://www.bluetooth.com/blog/bluetooth-pairing-part-1-pairing-feature-exchange/)
3. https://github.com/cypresssemiconductorco/CypressAcademy_WBT101_Files
4. https://www.bluetooth.com/specifications/bluetooth-core-specification/
5. https://community.cypress.com/community/training-videos

Thanks,

-Dheeraj

[ViBe_4457111]

Hello Dheeraj,

Thank you for your inputs. I have gone through Bluetooth standards, but bit confused. Last query on this topic is

As mentioned above, in BLE we have option either to have Pairing or Bonding. Whereas in Bluetooth though pair & bonding are present still keys are stored in both devices (Bonding). So in Bluetooth I cannot avoid Bonding. Please clarify on this statement.

Because when I pair Bluetooth device with my Windows PC, I am seeing pairing with keys stored. With BLE I am able to control either to have only Pairing or Bonding (Pairing is part of Bonding). Once I reset my phone, if BLE pairing, I need to pair once again. Whereas in Bluetooth even if I say pairing, whether it is Bonding by storing keys.

Also I have gone through below link and it explains details about BLE secure connection. As part of BLE paring I can skip phase-3. Whether the same possible in Bluetooth.

https://www.bluetooth.com/blog/bluetooth-pairing-part-1-pairing-feature-exchange/

Thanks & Regards

Vishnu Beema