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Aside from it being technically trivial to get an IP back from its hash, the EU data protection agency made it very clear that "hashing PII does not count as an
by WhyNotHugo 3y ago
Aside from it being technically trivial to get an IP back from its hash, the EU data protection agency made it very clear that "hashing PII does not count as anonymising PII".
Even if you hash somebody's full name, you can later answer the question "does this hash match the this specific full name". Being able to answer this question implies that the anonymisation process is reversible.
- kevincox 3y agoI think the word "reversible" here is being stretched a bit. There is a significant difference between being able to list every name that has used your service and being able to check if a particular name has used your service. (Of course these can be effectively the same in cases where you can list all possible inputs such as hashed IPv4 addresses.) That doesn't mean that hashing is enough for pure anonymity, but used properly hashes are definitely a step above something fully reversible (like encryption with a common key).
- deleted 3y ago[deleted]
- SamBam 3y agoI'm not sure the distinction is meaningful. If the police demand your logs to find out whether a certain IP address visited in the past year, they'd be able to find that out pretty quickly given what's stored. So how is privacy being respected?
- pluto_modadic 3y agoif it fulfills the same function, does it matter? if you have an ad ID for a person, say example@example.com, and you want to deduplicate it, if you provide them with the names, the company that buys the data can still "blend" it with data they know, if they know how the hash was generated... and effectively get back that person's email, or IP, or phone number, or at least get a good hunch that the closest match is such and such person with uncanny certainty de-anonymization of big data is trivial in basically every case that was written by an advertising company, instead of written by a truly privacy focused business. if it were really a non-reversible hash, it would be evenly distributed, not predictable, and basically useless for advertising, because it wouldn't preserve locality. It needs to allow for finding duplicates... so the person you give the hash to, can abuse that fact.
- bayindirh 3y agoWe're members of some EU projects, and they share a common help desk. To serve as a knowledge base, the tickets are kept, but all PII is anonymized after 2 years AFAIK. What they do is pretty simple. They overwrite the data fields with the text "<Anonymized>". No hashes, no identifiers, nothing. Everything is gone. Plain and simple.
- spookie 3y agoKISS That's the best way to go about it
- infogulch 3y agoI think it would be reasonable to at least number different participants so you don't completely lose the flow of conversation.
- bayindirh 3y agoDesign of the helpdesk keeps the dialogue intact. So no context or flow is lost in that particular case.
- jefftk 3y agoIt depends. For example, if each day you generate a random nonce and use it to salt that day's PII (and don't store the nonce) then you cannot later determine (a) did person A visit on day N or (b) is visitor X on day N the same as visitor Y on day N+1. But you can still determine how many distinct visitors you had on day N, and answer questions about within-day usage patterns.
- ilrwbwrkhv 3y agoYes but if the business is not in the EU they don't need to care one bit about GDPR or EU.
- troupo 3y agoIf they target residents of the EU, they must care. Edit: This is a different bear: Also, Bear claims to be GDPR compliant: https://bear.app/faq/bear-is-gdpr-compliant/ https://bear.app/faq/bear-is-gdpr-compliant/
- TylerE 3y agoIs an ipv4 address really classes as PII? Sounds a bit insane.
- beardog 3y agoIt can be used to track you across the web, get a general geographic area, and if you have the right connections one can get the ISP subscriber address. Given that PII is anything that can be used to identify a person, I think it qualifies despite it being difficult for a rando to tie an IP to a person. Additionally in the case of ipv6 it can be tied to a specific device more often. One cannot rely on ipv6 privacy extensions to sufficiently help there.