Hashed email addresses transmi琀琀ed to a digital data pla琀昀orm Hashed Identi昀椀ers DATA DIGITAL DATA OWNER PLATFORM Characteristics Effects On Privacy • Persistent and reusable hashed √ Underlying identi昀椀ers are obfuscated identi昀椀er used for matching purposes X Re-identi昀椀cation risk to all identities • Data trading partners gain access since hashed identi昀椀ers can be to all hashed identi昀椀ers mapped to external databases • One party lacks all control over the mapping X Hashes serve as pseudonymous rules and security of the data transmitted identi昀椀ers and may be classi昀椀ed • Trust is needed, since identifying as personal data transfers data can be leaked X Inequitable control over mapping process between sender and receiver Security Matrix Personal data To the data trading partner Are unknown identities exposed? Yes. The entire audience is transmitted. Can identities be re-identi昀椀ed? Yes. Stable hash values can be accumulated for later matching. Copyright © 2020 Karlsgate Inc. All rights reserved. 5