A friend had an idea about using some kind if strong mechanism of identity for combating spam, seo, information warfare, etc. All of those rely on the low cost

A friend had an idea about using some kind if strong mechanism of identity for combating spam, seo, information warfare, etc. All of those rely on the low cost of pretending to be unique and something else than the actuality combined with massive automation. However, ultimately (at least for now) everything is done by one of us 7.8 billion and each of us has a limited capacity for original content. Assume that content could be linked to identities and there were sufficiently strong guarantees that fake identities are not being mass manufactured by bot nets etc. Then something akin to a web of trust or credibility rankings could be established. Of course, the theory and the implementation of the identity mechanism would have to be strong, decentraliced and ridiculously easy to use and verify. Otherwise it would be abused in all possible ways simply due to being a high value target (or it wouldn’t gain momentum). Options for pseudonyms and anonymous publishing could be necessary to gain momentum and wide acceptance. Also recovering from identity theft would have to be possible.