Privacy

Privacy of transactions is a much desired property of blockchains. However, due to its very nature, especially in public blockchains, everything is transparent, thus inhibiting its usage in various industries where privacy is of paramount importance, such as finance, health, and many others. There are different proposals made to address the privacy issue and some progress has already been made. Several techniques, such as indistinguishability obfuscation, usage of homomorphic encryption, zero knowledge proofs, and ring signatures. All these techniques have their merits and demerits and are discussed in the following sections.

Indistinguishability obfuscation

This cryptographic technique may serve as a silver bullet to all privacy and confidentiality issues in blockchains but the technology is not yet ready for production deployments. Indistinguishability obfuscation (IO) allows for code obfuscation, which is a very ripe research topic in cryptography and, if applied to blockchains...