If the same blockchain technology that Bitcoin runs on is used for Quantified Prestige, then each esteem transaction will be visible in the public ledger. Within the Bitcoin ecosystem users can maintain some degree of anonymity (or pseudonymity) by creating many addresses that aren’t connected to one another.
In QP the Sybil protection mechanisms are not quite the same as in Bitcoin. They are primarily based on networks of trust and networks of esteem. Nodes (addresses) in a QP network are socially validated, so it’s not easy at all to create many accepted nodes at once – which is a design decision that is supposed to prevent Sybil attacks in the form of inflated Esteem point counts per real person. The downside of that very necessary design is that it becomes very hard to stay anonymous on a QP network.
Visibility through blockchain analysis
All your esteem transactions would be visible to the blockchain and become connected to one virtual or real identity. Everyone could analyse your pattern of esteem allocation, thus getting a pretty good picture of your personal preferences and social connections. That information would be tremendously useful for marketers and those who want to blackmail you for allocating esteem to “questionable” groups or individuals. The threat of that happening would make users distort their displayed preferences in the QP network in order not to reveal their true preferences out of fear of negative consequences for themselves. That would result in some kind of “market” failure: People don’t get exactly what they want, because Esteem points are misallocated.
A way to make blockchain analysis more complicated, and thus provide some degree of anonymity would be to use a large number of anonymous nodes, which forward Esteem points and don’t have an official “owner”. Only the person with the private key to the node would be able to set up the Esteem forwarding rules for such an anonymous node. However, this strategy probably wouldn’t help much, since it is to be expected that when a user allocates Esteem to an anonymous node that this node is under the control of the user in question. After all, there is little incentive to allocate Esteem to an anonymous node that is not under your own control – unless this approach is actually combined with the following one:
A different way to approach the problem is to create “anonymizer” nodes in the QP network which receive Esteem points from many different users and forward/allocate them according to the preferences of each individual user, without those preferences being visible in the regular QP blockchain! In other words: This anonymizer node would possess information that is not accessible to the public blockchain, thus introducing an element of partial centralization. The Esteem allocation information would need to reach the anonymizer node by a different channel than via regular blockchain transactions in order to stay hidden. There would also probably be the necessity to include temporal lags in Esteem allocation in order to prevent simple backtracking of where the Esteem actually came from.
Of course, persons using anonymizer nodes would have to trust those nodes not to sell or reveal their Esteem allocation patterns. This poses a significant obstacle to establishing or even automating such anonymity services.
Living with transparency
Another real possibility is simply accepting that one’s preferences are exposed on the blockchain. The more our societies learn to respect the personal choices of people without judging them too harshly for them, the more this becomes an acceptable option. Destructive criminal activity would still be punished, but everything else should get a free pass. Sadly, our world doesn’t show very clear signs of becoming extremely tolerant and open-minded, so we will have to deal with mechanisms that limit the damage from the evaporation of privacy.
Are there other ways to grant QP users anonymity without undermining Sybil protection at the same time?
Edit: I’ve been pointed to a method that can be used to at least hide the amounts of transactions: https://people.xiph.org/~greg/confidential_values.txt