If the node operators in the Blocksense network were able to delay or prevent the updates of certain price feeds, this would create an avenue for inducing an on-chain price disrepancies that can be potentially exploited in arbitrage trading.

The Blocksense network makes such an attack nearly impossible by dividing the work of publishing blocks between three separate roles within the protocol:

* The reporters in the network are responsible for determining their oracle reporting duties and executing the respective oracle scripts in a timely manner. The reporters are incentivised to publish an update that agrees with the majority. Skipping an update or reporting an incorrect value results in penalties. Thus, a reporter cannot individually censor any data feed because by definition each update will be signed by a large majority of reporters.

* The aggregators monitor the gossip channels in the network where the reporters broadcast their signed data feed updates. They are incentivised to package as many updates as possible in bundles that are re-broadcasted to the network. If an aggregator attempt to censor a certain data feed by pretending that she hasn't received the signed updates of the reporters, it's likely that another aggregator will include the feed update in their bundle in order to claim the associated rewards.

* The block builders are responsible for mechanically combining the bundles produced by the aggregators in the final blocks that will be published on the target chain. In this process, the block builder is not allowed to manipulate the contents of the mixed bundles in any way and this is ensured through a zero-knowledge circuit that verifies that each block is constructed correctly.

A block is considered valid only if a sufficient number of aggregators have contributed to it. Please note that the same data feed update is likely to be present in the bundles of many individual aggregators and this makes it exceedingly difficult for the builder to construct a valid block where specific feeds are missing. In each slot, multiple builders are eligible to publish a block and this ensures that even if a particular builder is offline, others will step in to publish a valid block including updates to all feeds.

The different roles in the protocol are not pre-determined, but rather dynamically and randomly assigned to the node operators as time shifts. The Blocksense node software automatically keeps track of the role assignments and performs all duties accordingly.