Zooko's triangle

Zooko's triangle defines the three desirable traits of a network protocol identifier as Human-meaningful,, Decentralized and Secure.

Zooko's triangle is a trilemma of three properties that are generally considered desirable for names of participants in a network protocol:^[1]

• Human-meaningful: Meaningful and memorable (low-entropy) names are provided to the users.
• Secure: Any entity in the system can act maliciously, including the majority of the entities or the available computational power.
• Decentralized: There is still only one, unique and specific entity to which a name resolves.

Overview

Zooko Wilcox-O'Hearn conjectured that no single kind of name can achieve more than two. For example: DNSSec offers a secure, human-meaningful naming scheme, but is not secure against compromise by the root; .onion addresses and bitcoin addresses are secure and decentralized but not human-meaningful; and I2P uses name translation services which are secure (as they run locally) and provide human-meaningful names - but fail to provide unique entities when used globally in a decentralised network without authorities.

Solutions

Several systems which exhibit all three properties of Zooko's triangle have now been created, including:

• Computer scientist Nick Szabo's paper "Secure Property Titles with Owner Authority" illustrated that all three properties can be achieved up to the limits of Byzantine fault tolerance.^[2]
• Activist Aaron Swartz described a naming system based on Bitcoin employing Bitcoin's distributed blockchain as a proof-of-work to establish consensus of domain name ownership.^[3] These systems remain vulnerable to Sybil attack,^[4] but are secure under Byzantine assumptions. Namecoin now implements the concept.

Several platforms implement refutations of Zooko's conjecture, including: Twister (which use the later Aaron Swartz system with a bitcoin-like system), Blockstack (which can run on any blockchain and currently uses Bitcoin), Namecoin (separate blockchain), and Monero OpenAlias.^[5]

See also

• OpenAlias
• Namecoin
• Blockstack
• Petname
• GNU Name System

References

External links

• Zooko Wilcox-O'Hearn, Names: Decentralized, Secure, Human-Meaningful: Choose Two – the essay highlighting this difficulty
• Marc Stiegler, An Introduction to Petname Systems – a clear introduction
• Nick Szabo, Secure Property Titles – argues that all three properties can be achieved up to the limits of Byzantine fault tolerance.
• Bob Wyman, The Persistence of Identity: Updating Zooko's Pyramid
• Paul Crowley, Squaring Zooko's Triangle
• Aaron Swartz, Squaring the Triangle using a technique from Bitcoin