[jimmygrapes]

I am no expert on GDPR or security, but wouldn't a simple "PII to Cryptologically Secure Hash" solution work for some of this? The PII would possibly need to be accessed piecemeal while the account is active, so hashing is not appropriate alone, but once the account is deleted you could store a user's hash (or partial hash, made from only truly unique info or info combos) since it cannot be reconstituted and contains no specific PII. You then store this hash in your "abusive person" list, or whatever, maybe link it to refund data if needed, and if a "forgotten" user needs to interact with the service they fill in their information which is converted to the hash without saving. Doable?

[NiceWayToDoIT]

There are two issue with hashing I can envisage:

1. Nothing user has is truly hash-able, (email can be replaced, there are people with the same name/dob/place of birth, address is not permanent attribute...)

2. Hash key can have duplicates - so those collisions would block different users (probably not for small companies but for FB with 2 billion users something worth considering.)

[jeffffff]

this doesn't cut it. someone could take a list of email addresses, hash them, and then reidentify the dataset. hashing buys you nothing from a gdpr/ccpa compliance perspective, storing the hash is seen as no different from storing the pii itself. it really only makes things harder because it becomes more difficult to find where all the pii is when someone submits a request for you to return or delete their data.

[ahofmann]

Do you have a source for this? I thought for the gdpr it was enough that data is not easily accessible. For example, it is not necessary to delete PII from backups unless they can be automatically restored (and are reasonably encrypted). Hashing PII thus falls under this category.

[jeffffff]

i don't have a source i can link here, this is guidance i have gotten from lawyers.