What is device linking?
Device linking is the graph of which customer accounts have been seen on the same device fingerprint (and sometimes the reverse: which devices a customer has used).
Why a fingerprint alone is not enough
A hash without a join to customer external ids cannot tell you “this phone opened four wallets.” Persist both keys on every event. Product copy describes flagging devices linked to multiple accounts.
How to operate it
Thresholds belong in named rules: three or more customers on one device in a week is REVIEW, not automatically BLOCK. Families and internet cafes exist. List the fingerprint after an analyst confirms a farm.
Naiza’s role
Attach the SDK fingerprint to signup, login, and payout. Use lists for confirmed-bad devices. Confirm the current multi-account threshold in docs instead of copying a marketing number into policy.
Frequently asked questions
Short answers written so search and answer engines can cite them.
What is device linking in fraud?
It is associating one device identifier with many user accounts so multi-accounting and shared attack tooling become visible.
Is device linking a social graph of people?
No. It is a risk graph of identifiers. Do not treat it as proof that two legal persons are the same without investigation.
How is it different from fingerprinting?
Fingerprinting creates the identifier. Linking is the many-to-many join to customers over time.