They tell me web3 is better. They say that we're taking back control of the internet. We're taking control of our digital stuff. WE control the memes now. That's great! Let me in! This is the place I want to be. But, why are you stalking my address on Etherscan? Why am I afraid when you see the Metamask icon on my phone? No, please don't look at those dodgy mints I aped into. Don't judge me for my defi-summer plays. What do you mean you don't trust my voting rationale? But is it safe to use mixers?

Web2 was plagued with predatory practices that arose from masses of data sitting in centralized systems, and while Web3 aims to circumvent that by removing the central point of trust, we see new problems arising. Transparency and verifiability are the drivers of healthy decentralized financial and governance systems, but are they necessary to facilitate an individual's daily movements online? Is there a way that users can have privacy? Beyond that, as systems become more abstract and complex, is it easy to use and maintain that privacy?

In this talk, we'll categorize some blockchain privacy problems, from the protocol level to the individual, and introduce recent cryptographic innovations that help to mitigate them. We'll show how they can be used build scalable decentralized applications for a variety of purposes, including preventing front-running attacks on DeFi platforms, end-to-end encryption for decentralized messaging and social networks, cross-chain bridges, as well as advanced cryptographic primitives such as witness encryption and one-time programs that previously could only be built from secure hardware or using a trusted third party.