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by slykar 2133 days ago
I've listened to a podcast interview with a lawyer specializing in EU privacy laws and he said that it does not matter if the personal data is hashed or encrypted. It's still personal data. This was about data stored in a database tough, but browser local storage is a database.

This was mentioned when the guest spoke about right to be forgotten. The law is really weird, because you need to delete user's data from your database, but it's OK to keep backups.

> It is the same data that is found in server log files. In the strictest interpretation of GDPR, I don't think any analytics product can exist.

It can exists as long as user agrees to be tracked. There is a category of "metrics" "cookies" user needs to agree on before you can track him for metrics. That's the whole point of the law. You need user's permission.

2 comments

> 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.

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.
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
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.
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.

Without correlating data it really isn't "personal" though. You could delete the User account and related without touching this product and you've complied because this data could then never be correlated. Also, if nothing in the activities leaks the user's own identity, then again wouldn't really be personal.

IANAL