Social Oracles can either be people or machines. A set of social oracles are chosen at random to evaluate an ad’s fitness for publication within a time-space-location. The number of social oracles chosen depends on the size, duration, channel and distribution of the ad.
In the Bitfari Whitepaper, social oracles are mentioned as people or machines that maintain ad quality. We now from the network incentives post that human social oracles are either pre-auditors or onsite auditors but what are machine oracles?
A computerized social oracle is a small program living in the Bitfari blockchain that automatically audits ads. The main social oracles are:
– Word filter. Its a computer program that bans bad words for a given language. In United States for example, the ad cannot contain bad words in English or Spanish or the language-social-oracle would ban it.
– Phrase filter. Its a computer program that bans bad phrases for a given language. In United States for example, the ad cannot contain bad phrases in English or Spanish or the phrase-social-oracle would ban it.
– Velocity filter. A program that analyses the posting speed of publishers to monitor and avoid DOS attacks. Roughly speking any increase by more than 500% in the average speed of posting will be disuaded from posting for 1 hr.
– Bogus ad filter. Variant of the aforementioned DOS attack. the bogus-social-oracle blocks posts containing non-existent words, words with signs in between (B@D W*RD, etc).
– Censorship resistance. Onsite auditors want to block an ad because they don’t like it eventhought preauditors approved it. The ads stands as social oracles have a tally of preauditing. However the screen is flagged for review by a different auditor with a different ad.
– Collusion resistance. Preauditors collude and eventhough they are chosen at random they block every ad booked to the platform on a given day following guidance from a reddit thread. Blocked ads are shown to the store-owner/billboard operator and they can choose to show it. The collusion-resistance-social oracle flags and keeps track of the even. This oracle will lower the karma of auditors reducing their bounty earning probability.
– Screen blocking. If a screen is declined by an auditor the first time is audited the owner will have to request a secound audit with can happen withint 24hrs. Let’s suppose the screen was approved the second time and has been running for a month. A client reports a screen broken, but it is not. An auditor is requested and says the screen is broken to keep the prank going (because Reddit). The screen owner sends a picture to the ad poster thru the social oracle and the agency validates the screen is working. Case closed. However, if within the agency somebody is a friend of the pranksters, maybe they can decline to show the ad.
In either case there is significant economic loss to assume this type of cases will not only be rare but easily fixable with a second submission.
Two important caveats:
- Bitfari can run perfectly without auditors just with machine oracles and screen owner supervision. The advantage of auditors is providing feedback to advertisers and notices to screen owners, they produce data that is subsequently warehoused and offered to advertisers at no cost.
- Computerized social oracles are not limited to this list. We plan to keep adding more to increase the speed of the system and avoid fraud. Different jurisdictions may require new oracles to comply with new or forecoming legislations.