[Aeolun]

> it does not matter if the personal data is hashed or encrypted

That sounds odd. If there is no way to go back from the hash to the data it is no different from a random string of letters and numbers.

[johncolanduoni]

It’s different because it allows reidentification. It prevents you from coming up with an IP or what have you out of thin air, but you or another party you give it to can effectively use it as a perfect proxy of whatever you hashed.

[sinsterizme]

Let’s take a hashed IP address.There are 4.3B ipv4 addresses. So a few minutes on an old laptop to generate a rainbow table. With decent hardware it would be seconds. The rainbow table could then be used to identify all the IPs you store. If they are salted, then each IP would need to be brute forced, but still only seconds on good hardware

[tracker1]

That would still take collaborative data from another dataset outside this product. Compliance would be up to whoever hosted this, and the collaborative data set to comply with the request anyway.

[PinguTS]

Did you remember when an old data set from AOL was released where the user id had been pseudonymised by some hashing?

The users could be re-identified just by their behavior.