Did philosophers not watch Blade runner? Sure Descartes didn't - but contemporaries sure as shit do!
Paraphrasing from memory: he pins "cogito ergo sum" on the assumption that objective knowledge is possible. That assumption is built atop imagining an alternative: an evil demon has full control over his senses and feeds him whatever it wants to (essentially, the 'Matrix hypothesis'). His solution to this concern? "A loving God wouldn't create a universe that banal and meaningless."
It's only a proof if you accept the postulate that objective reality is correlated with experience.
To answer your question, I claim that you can't. Radical skepticism ("we live in the universe of the evil demon"), which is what I advocate for, means that you can't even claim that you exist. See the works of Max Stirner for further elaboration of the implications of this for Philosophy.