Since I wrote the first article in this two-part series, a lot has come to light regarding the use of mobile user IDs — especially Android ID, of which the public knows little about compared to the far more publicized Apple UDID and IDFA. In closing out this user ID targeting series, we’ll dive into Android ID and discuss the future of user identification in the mobile industry.
Understanding Android ID
Android ID is a software identifier that changes every time an Android device is reset to its factory settings. It has emerged as the leading choice amongst publishers in utilizing Android user identification.
In order to properly leverage Android ID, publishers typically pass it in a SHA1 hashed form of the ID (a favored obfuscation technique), which allows for anonymity and greater privacy. This characteristic of the hashed Android ID makes it much more desirable than a hardware-based identifier, which typically raises privacy concerns.