Muppet Reputation Mechanism

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Muppet Reputation Mechanism

• Juho Heikkilä
• 16.3.2007
• HELSINKI INSTITUTE FOR INFORMATION TECHNOLOGY
• HELSINKI UNIVERSITY OF TECHNOLOGY

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Muppet in Nutshell

• Managing Privacy and Trust in P2P Communication
• Cases Online trading / Media production
• Human centered mobile devices/services
• Distributed, no central trust server
• Peer reputation (human/service/media)
• Past actions as a basis for trust
• Economic and security

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What is (our) reputation?

• Reputation is information about prior acts
• It is subjective and incomplete
• Subjective in use case and in social context
• Incompleteness is not a flaw but a natural
  phenomenan
• Personalized estimation on known data
• How does it look to this user and in this context

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Goals of Reputation

• In financial scenarios maximizing trade
• Basically we want to encourage
• Producing media
• That others are interested in too
• Reputation works by giving points
• Spam / Building anti-spam incentives
• Spam is annoying to see
• It can ruin your whole media/channel

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Formation First Persistent Object

• Reputation should primarily be gained by the
  nearest object that is persistent
• Trade is not persistent, seller/buyer is
• Book is persistent
• Song is persistent, performance is not
• Recording of a performance is, however
• Multiple different recordings of one event
• Persistence is not always trivial

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Inheritance of Reputation

• Things are easier to evaluate than people
• Even in eBay we evaluate trade, not partner
• We do not know anything else about him/her
• Even traitors do good deals (and vice versa)
• Single action does not fully present anyone
• Reputation is inherited from things
• Higher level entities inherit from basic blocks
• Event ? FPO ? Combinatory entity