Sentry is an app developed by Hala Systems that provides civilians with a crowdsourced and sensor-controlled early warning system against air strikes during the protracted civil war in Syria.
Live since 2016, the system has become more precise and complex. It uses a sensor network, artificial intelligence and blockchain technology to create a strong technological foundation for analyzing data on site and distributing critical warnings. Sentry now issues an average of 140 early warnings per day, so that citizens are informed of possible dangers between seven and ten minutes in advance.
The data inputs to the warning system include observations and reports from people, such as sightings from overhead aircraft, and sensor modules placed in trees or on roofs that collect acoustic data for analysis. In addition, neural network systems search local social media for keywords that can provide further clues as to the time and location of possible attacks.
So far, Sentry has used the Ethereum blockchain to provide a distributed and secure means of reviewing and storing the metadata attached to these various data entries, including their geotags and timestamps. In addition, blockchain technology was an important tool to prove that input data was not later tampered with.
This is especially important as the amount of real-time data Hala Systems has collected on strikes and attacks could become an important source of evidence in the future for organizations seeking justice to eradicate war crimes. As a private company whose data retention could prove problematic in this regard, Hala Systems has therefore worked with decentralized technologies such as Ethereum (ETH) to ensure that the data is verifiably tamper-proof from a legal point of view.
In a conversation with Cointelegraph, a representative from Hedera Hashgraph said that Hala Systems has now decided to stop using Ethereum in favor of the Hedera Consensus Service, as the former had been found to be insufficiently tamper-proof. They declared:
“Hala Systems […] found [Etherum’s] probabilistic (not final) consensus, smart contracts with very variable fees, and slow confirmation times that are unsuitable for their use case. “
The Hedera Consensus Service, the company said, provides a more efficient, immutable chain of custody for the data entered into the system – and provides evidence that third parties can trust about who is, where, and what of an event.
“Hala Systems can provide real evidence and evidence of when and where media originated. Every event logged at the HCS is signed with the keys of the issuing camera and receives a consensus time stamp from the entire Hedera network. ”
In addition to its technology partnership with Hedera Hashgraph, Hala Systems also works with the United Nations, the UK Department of State for Commonwealth and Development, the US State Department and other State departments. In an analysis of numerous offensives in northwestern Syria since 2017, the use of the Sentry app was reportedly correlated with an “average reduction in net accident rates due to air strikes of 10-30%”.
The Hedera platform itself is led by a council of largely private partners, including Boeing, Deutsche Telekom, Google, IBM and Nomura, and University College London.