Providing pure ex-ante (pre-execution) versus pure ex-post (post-execution) DP guarantees in differential privacy mechanisms has different implications based on when the privacy analysis is conducted:
Ex-Ante DP Guarantees:
Pure ex-ante DP bounds are established before executing a mechanism.
These bounds offer upfront assurance about how much information leakage or loss of privacy might occur during operation.
Ex-ante guarantees help in setting appropriate parameters beforehand to meet specific levels of data protection.
Ex-Post DP Guarantees:
Pure ex-post DP bounds are determined after running a mechanism and observing its outputs.
They reflect actual data usage scenarios and provide insights into how much private information was potentially exposed during execution.
Ex-post guarantees allow for retrospective assessment and adjustment if necessary based on observed outcomes.
The choice between these two types of guarantees depends on factors such as operational requirements, transparency needs, regulatory compliance, and overall risk management strategies within an organization or system.