The evolution from V1/V2 to V4/V5 represents Huawei's transition to more complex, secure hashing methods. V4 Algorithm
The "V4" and "V5" designations refer to different revisions of Huawei's unlocking algorithms. They are primarily used for 3G and 4G USB modems, MiFi portable routers, and some home broadband routers. huawei v4 and v5 unlock code calculator by imei