User Perceived Privacy in Blockchain: A Personal View
People want privacy of transactions because they don’t want to be extorted, blackmailed, robbed, or even kidnapped. However, there could be other reasons.
Probably, you haven’t given blockchain privacy a deeper thought, or you haven’t yet seen reasons for blockchain privacy. If any of the two applies to you, don’t worry, this comment has you covered.
Here, I’ll answer the research questions (RQ) from the original paper. That’s, I’ll answer questions on how familiar I’m with privacy issues and technology, how willing I’m to use privacy techniques, and which privacy features interest me the most.
I hope that in answering these questions, you might get a better understanding of blockchain privacy if you don’t. My answers might give you reasons to buy the idea of blockchain privacy, who knows?
RQ 1: On Familiarity with Privacy Issues and Privacy Enhancing Technologies
There are two kinds of third-party services— centralized and decentralized third-party services. I’m not interested in centralized services for the reason that they defeat blockchains’ goal of decentralization and can easily be manipulated.
I’m, therefore, an advocate of decentralized third-party services for the mere reason that they are decentralized and not easily manipulated. Even after the US’ ban of Tornado Cash mixer, a decentralized third-party mixing service, the protocol is still running. Maybe, if it were a centralized service, it would have been shut down.
In addition, some blockchains can come with privacy added features, while others have privacy inbuilt as in Monero and Zcash.
Personally, investing in a blockchain’s native currency for the reason that it has an inbuilt privacy feature is not ideal for me. I prefer to invest in coins of native blockchains, whose use cases excite me, and which can add privacy, aka add-on, as a necessary feature.
Imagine if Bitcoin or Ethereum had an add-on privacy feature, users will most likely prefer them over in-built privacy blockchains, like Zcash or Monero, as they have more use cases, user base, fame, trust, market cap, etc.
RQ 2: On Using Privacy-Preserving Techniques Amidst their Challenges
Privacy-preserving techniques use special mechanisms such as cryptography to ensure privacy on a blockchain. Such techniques include ZK SNARKs, Ring Signatures, etc. This research summary by @Tolulope lists and explains the various privacy-preserving techniques on Bitcoin and other cryptocurrencies.
Techniques like Zero Knowledge Proofs are very popular for their success. I have researched a handful of these techniques and I can say that I’m comfortable with their modes of operation. They can be easily adapted to a blockchain and can be the basis for add-on features. Remember, I prefer the add-on privacy feature on blockchains in the first place.
RQ 3: On the Best Privacy Feature as a User
In choosing a privacy feature, a user has to choose what is most important to them. Intent matters a lot and one should always ask, why do I need privacy in the first place?
As outlined in the research summary, such privacy features are: hiding the source, hiding the destination, and hiding the amount. So, choosing any of these as the best feature would depend on what one wants to hide and for what reasons they want to do that.
Personally, at this time, I’m only interested in hiding the amount of my transactions. I don’t care if the recipient address on the sender’s address is known, but I don’t want the amounts on my transactions left in the open. This is mainly for security reasons.
Conclusion
Just like @Jmax stated in his recent comment, blockchain privacy depends on who is involved. What one considers as part of privacy might not be the same for others. This post tried to cover my view of privacy and hopefully help you discover or improve yours.
If you enjoyed reading this, you may directly reply to this post. Let’s keep the conversation going.