encryption and decryption of advertising data

[Naralasetty Praneeth]

Hii nordic;

I need to encrypt and decrypt my advertising data i.e;UUID,Major,Minor,etc.;  of my nrf52832

So it cannot be seen by third parties

my sdk version is 15.2 and softdevice is 132

[bjorn-spockeli]

Hi Naralasetty, 

you can use the ECB peripheral to encrypt the advertisement data. See our Intro to Application-level Security Using the ECB Peripheral blog post. 

Best regards

Bjørn

[Naralasetty Praneeth]

Hi bjorn, 

I need the code for latest soft device 132  

[Naralasetty Praneeth]

bjorn-spockeli: 

We are working on an application based on Id cards which broadcasts its information and gateway reads the information it and sends to a server. Now the problem is that the ID card's information should not be cloned by any third party.

[bjorn-spockeli]

Understand. 

As I stated in my previous reply, exchanging the nounce and keeping counters in sync is complicated when only doing advertisement. The added complexity cannot really be justified when you're only encrypting two 16 byte buffers on boot and then keeping the advertisment data static. 

My suggestion would be to create a unique key for each device and then simply use sd_ecb_block_encrypt to encrypt the advertisment data. The central would then hold a copy of each unique key and then use the same function sd_ecb_block_encrypt to decrypt the data. 

Best regards

Bjørn

[Naralasetty Praneeth]

bjorn-spockeli: can you give me code for peripheral and central if available

[kathleenlai]

Hi Bjorn, would like to know what's the different calling 

ctr_encrypt(m_beacon_info);
ctr_encrypt(&m_beacon_info[16]);

we necessary have to do this twice to encrypt ?

Thank you. 

Regards,

Kathleen

[codebreaker176]

Hi,

Can you please tell why are you using ctr_decrypt() function twice for the same data in the above code?

ctr_decrypt(m_beacon_info);
ctr_decrypt(&m_beacon_info[16]);

And is it necessary to add " case BLE_GAP_EVT_ADV_REPORT: "   within

switch (p_ble_evt->header.evt_id) ?

Also 

scan_start();

Are we supposed to add the above function as well?