MOVED TO THE REPOSITORY

What are Sybil Attacks and why we should fight them?

The name Sybil originated from a medical case of a woman called Sybil, she was diagnosed with multiple personality disorder. Sybil attack is a kind of "fraud" that occurs on systems/organizations where actions and rewards are calculated based on "one human, one identity", fraudsters or 'sybils' create multiple identities in an attempt to control (vote) or profit (distributions of funds or rewards). Fighting this kind of practice enables organizations to have democratic practices without the physical presence of its participants, for example online voting in DAOs.
For more in depth discussion you can check:

• 33 - Sybil Resistance with Bryan Ford ( at 14:00 they start to discuss possibilities in a world where we would already solved the sybil attack problem)

What is quadratic funding and matching? Why is it important to understand Sybil attacks?

Image is better than a thousand words,right? Check this 60 sec video by Gitcoin and come back here:

• WTF is Quadratic Funding?

Nice, now that you understood, is easy to get why fraudsters create multiple accounts. The idea is simple, make really small contributions to their own project from different accounts in an attempt to maximize ROI, as quadratic funding algorithm prioritize distribution of matching funds pool to projects that received donations from the biggest number of community members.

What is the price of forgery?

Price (or cost) of forgery, as it says, is the cost paid to forge an identity in a system. There are a lot of discussions about economic games involved in sybil defense. Most systems are designed to develop a high cost of forgery in an attempt to disincentivize sybils attacks, making the attack expensive and not profitable. Some discussions argue that this could stop sybil attacks focused on profit but if the motivation is other, like ideological, cost could not be a barrier.

In ep 36 of Green Pill podcast, Kevin Owocki and Petr Porobov, founder of Upala, have some discussion around the topic and how Upala is trying to understand the real price of forgery using incentives.

• 36 - Creating Sybil Resistance with Upala Founder Petr Porobov

Where can I find more sybil fighting content?

• Gitcoin Fraud Defense and Detection Forum
• Green Pill Podcast- Season 2 is dedicated to regenerative society, some episodes are focused on Digital Identities and Sybil Fighting
• BlockScience Blog- Articles with analyses of passed Gitcoin Grants Rounds and other complex system analyses.
• Prof. Brain Ford Papers - Prof Brian Ford has studies on decentralized systems, identity and blockchain. Special highlight to: Identity and Personhood in Digital Democracy: Evaluating Inclusion, Equality, Security, and Privacy in Pseudonym Parties and Other Proofs of Personhood