Pseudonymization

A privacy technique in which personally identifying fields are replaced with artificial identifiers — typically hashes, tokens, or randomly assigned IDs — so that the data can no longer be attributed to a specific person without additional information kept separately. Recognised by GDPR (Article 4(5)) as a significant risk-reduction measure but not equivalent to full anonymisation. In accessibility research and products, pseudonymisation is often used to hash user IDs in chat logs, screen-reader telemetry, and assistive-tech usage data while preserving analytic value.