BLE security pairing

Hi,

1. What's difference between security mode 1 level 3 and 4?

--> This question does not make sense since mode 1 according to the spec "security mode 1 will never initiate any security procedure" while level 3 and level 4 needs to have MITM, Authentication...etc security procedures.

2. How should I do to modify BLE 2.02 security example to security mode 1 level 1?

--> It does not make sense to use a security example to do things that does not need security(mode 1 will never initiate any security procedure) 

Also only mode 4(security mode) shall classify the security requirements using the levels you mentioned.

Please take a look at Bluetooth Specification Vol 3 Part C section 5 Security Aspects.

Hi Christin,

what do you mean about mode 1 will never initiate any security procedure?

I found the table blow on the spec and I am really confuse now.

Wei Lu

I was checking another chapter.

I know where you are checking, I can understand your question better now.

The only difference for mode 1 level 3 and level 4 is the secure connection. Secure Connection uses Elliptic Curve Diffie-Hellman cryptography.

For your second questions :
2. How should I do to modify BLE 2.02 security example to security mode 1 level 1?
--> Again, there is no security, no authentication, no encryption. There is no need to use security connection example to achieve what you want. You basically just need a normal simple_peripheral + simple_central without pairing bonding, just connect.