Surprise surprise. It uses the serial number. Completely unobfusticated.
Ha! That's not a serial number. It's a QR code. What did you expect to find?
Oh, sure Dahua may call it a SN and may even use it as one, but that does not make it one.
Why? Because serial numbers strictly speaking are "serial", consecutive integers, like 1000,1001,1002 representing the order of manufacturer.
They have the property of predictability. These likely do not.
The "completely unobfusticated" serial number that you don't show is:
TZA4LF076WU17K2
And is a standard Alphanumeric single case 15 character encoding which yields:
221,073,920,000,000,000,000,000 unique values.
Take a guess how many devices Dahua actually has live in the p2p system and divide into the number above. That's how many non-numbers you have to go thru to get one good one. Probably 5 quadrillion or something like that.
I know you think its some standard Dahua scheme, so for more info here is how the one from my NVR starts:
1H0389D5...
If you still don't believe they are using a hash function, then it should be easy to prove. Just start incrementing different sections by one and then check them to see if they exist.
Remember this is base 36, so the next digit after 9 is A and keep going to Z:
- TZA4LF076WU17K8
- TZA4LF076WU17K9
- TZA4LF076WU17KA
- TZA4LF076WU17KB
Keep us posted on the first valid one you find.