This is how I did it. You generate a salt per logging context and combine with the base into a sha2 hash. The idea is that you ruin the ability to correlate PII across multiple instances in different isolated activities. For example, if John Doe opened a new account and then added a co-owner after the fact, it wouldn't be possible for my team to determine that it was the same person from the perspective of our logs.
This isn't perfect, but there hasn't been a single customer (bank) that pushed back against it yet.
Salting does mostly solve the problem from an information theory standpoint. Correlation analysis is a borderline paranoia thing if you are practicing reasonable hygiene elsewhere.
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This is how I did it. You generate a salt per logging context and combine with the base into a sha2 hash. The idea is that you ruin the ability to correlate PII across multiple instances in different isolated activities. For example, if John Doe opened a new account and then added a co-owner after the fact, it wouldn't be possible for my team to determine that it was the same person from the perspective of our logs.
This isn't perfect, but there hasn't been a single customer (bank) that pushed back against it yet.
Salting does mostly solve the problem from an information theory standpoint. Correlation analysis is a borderline paranoia thing if you are practicing reasonable hygiene elsewhere.