impact of encryption on battery performance

RE: impact of encryption on battery performance

bjorn-spockeli — Thu, 27 Apr 2017 11:33:56 GMT

Yes, our SoftDevices enable the Bias Correction of the RNG.

RE: impact of encryption on battery performance

Amit Chahar — Thu, 27 Apr 2017 09:53:18 GMT

Does softdevice random number generator function use bias correction?

RE: impact of encryption on battery performance

bjorn-spockeli — Thu, 27 Apr 2017 09:26:37 GMT

Q1: I cannot find any data on this in our internal Product Spec, so I would assume that the current consumption is either identical or lower.

Q3: Of course, sorry for that. We do not have any measurements showing the current consumption impact of using a RPA. Yes, the RNG is used for that and you can find the Electrical specifications for it here.

RE: impact of encryption on battery performance

Amit Chahar — Thu, 27 Apr 2017 09:12:38 GMT

Q1. Can you tell if the current consumption for AES-ECB module on nRF52 would be higher or lower than the current consumption by nRF51 ?

Q3. RPA means Resolvable Private Address. To generate a RPA, 3 random bytes are needed. I am assuming that softdevice uses RNG for these 3 random bytes.

RE: impact of encryption on battery performance

bjorn-spockeli — Thu, 27 Apr 2017 09:03:04 GMT

Hi Amit,

Q1: the run current of the AES ECB peripheral and the time it takes to encrypt a 16byte block on the nRF51 is stated in the nRF51x22 Product Specifications.

Unfortunatley, we do not have any run current measurements for the AES ECB module on the nRF52832, so you will have to measure this.

Q2: You can calculate the average current consumption of a single AES ECB block encrypt(i.e. 16bytes) by multiplying 550uA*8.5us = 4.675nA

Q3: RPA? Do you mean the Random Number Generator(RNG)?