CERT

CERT

= imei certificate = imei signature = imei key file. 

Most of all 2014/2015 year samsung phone have new security regarding imei. All phones out from factory with imei signature(key,cert) calculated in factory and stored in DB.

Qualcomm phones have more strong security and even not allow to read cert. Exynos phones allow read/write cert. SPD phones allow read/write cert.