Anti-sybil attack mechanisms

Uport (by Consensys and Microsoft)

Smart ID

Deloitte Opens Ethereum Identity Platform to Blockchain Developers



Q: Can I create 100 fake accounts that all trust each other and abuse the system?

A: You can create them but this will not create value. As long as nobody else trusts these accounts they can only exchange money with each other, rendering all the money worthless.

Web of Trust (Used by Duniter basic income)

Proof of individuality by (Johan Nygren)

Prevent Sybil attacks by having:

-Entry cost i.e. joining the network

-Existence cost i.e. staying in the network

-Exit penalty i.e. leaving the network

Reputation systems

people are indicated by other people to be persons, and once they have enough reputation, can indicate more people.

E.g. Quantified reputation system used in the Geoflux reputation system

Synchronized pulsed captchas

Computer-hard problems like captchas are used to help against sometimes. They are not fool proof. However, if you synchronizedly do it at the same time, it is harder to hire people or computers to emulate it.

BioAuthentication e.g. eye authentication or TouchID (iphone has Touch ID)

Proof of video meeting


Time stamped selfie:




Proof of phone (a kind of Know Your Customer- KYC)

Open source protocol used as a layer for indentity and reputation


I talked with Bitnation people and they told me that they will create from scratch a reputation system agnostic to blockchain based on SSBC.

It will be inspired by the philosophy of and probably will have common things with Uport,but it will be agnostic to blockchain (where Uport is based on Ethereum).

The things that prevents sybil attack is that it takes a long time to build up the reputation – hence it’s not in people’s interest to start from scratch.

Kind of like on e-Bay or It will be sometime in 2017 ready,however difficult to know the exact time .

A collection of identity projects


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