Identity for end users

Is there a way to identify a user (for example in a web app)?

If I have a wallet, is there a way to say “i’m a user[hash/uuid,whatever] and this is a string[signed hash/whatever] to confirm my identity”?

Such a way will violate one of the major tenets of Cryptocurrency…Anonymity. For cryptocurrency, tracking transactions is a good thing but tracking the users making these transactions is not good. So, I don’t think crypto will implement such features.

@DAPP360_MIKE this is probably just a misunderstanding and bad wording in my question.
wallets already do this, an end user can confirm that he owns ADA (or any other crypto) and can “log in”/claim an account/address w/ his key.

what i’m asking is not to identify a user by “first last name” (or anything similar) but to identify a returning user to a website based on a wallet address or something similar.

Ok. It should be as simple as checking if the website has the incoming wallet’s public key. If public exist in the website cache or db, most likely it’s a returning wallet. But remember the same user can visit the site with a different wallet generated from the same private key.