In this chapter, we continued our blockchain journey and explored the topics of security, privacy, and smart contracts, making it clear that we are not dealing with just an ordinary shared database. In the security section of this chapter, I explained that the blockchain is actually very secure, but it relies heavily on the way that you set up your network and the choice between a public and a private blockchain. I reviewed the unexpected security risks, the architecture of the network, the importance of the consensus protocol, how to store your assets securely, and how to control access.
In the next section of the chapter on privacy, I described what it takes to secure an individual's privacy on the blockchain. I discussed maintaining today's levels of privacy, from complex obfuscation to a simplified permissioned blockchain. I explained the available options, including cryptographically-secure obfuscation, indistinguishability obfuscation, secure multi-party computation, and zero...