What is the best combination of data to ensure the uniqueness of web users?
How can you ensure that the anonymous Internet users who voted using your polling system are unique (each anonymous user votes only once)?
I can think of:
1. client IP
2. Client machine name
3. MAC address
4. Cookie storage
As far as I know, you cannot get (2) and (3) in web development, and (4) is not guaranteed as user can delete / disallow cookies
Do you think it is better to achieve uniqueness?
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The only safe way to achieve uniqueness is for users to be logged in.
Using only IP addresses is not good enough as the IP address can be confusing and there may be multiple users behind the same IP address
Even the MAC address can be changed easily (there are free tools for it)
Cookies are obviously not very reliable
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I think that only a login system with external authentication (not IT, human system) will give a very high level of confidence, for example. support a vote for the government, but for the purposes of the lessor, the uniqueness of the browser should be considered
Web browsers leave "Fingerprints" when you browse the web Browser fingerprint may contain an ID without cookies
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Comment on ideas:
1) The IP address can be shared between many users (for example, my IP address is the same for the whole block of apartments ...) which could be a problem
2,3) yes, maybe not possible without some browser extensions or other similar things
4) cookies can be deleted, but some third party cookies (like iframe) can be easy ways because the user may not search for it in the list of cookies ... If I want to vote on example.com I probably , I won't be looking for a cookie from example2.com ... I hope I made it clear what I mean.
And I would add the browser agent string to the number 5.
But the other answers are correct, that registering with a mail confirmation code or something is most likely only a "safe" solution. But your question was anonymous, so ...
It is definitely impossible to be 100% sure that the user is unique ...
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