Delphi: Asynchronous Approximate Agreement for Distributed Oracles This repository contains a Rust implementation of the following distributed oracle agreement protocols. Delphi Asynchronous Approximate Agreement (AAA) protocol FIN Asynchronous Common Subset (ACS) protocol Abraham et al. AAA protocol The repository uses the libchatter networking library available here. This code has been written as a research prototype and has not been vetted for security. Therefore, this repository can contain serious security vulnerabilities. Please use at your own risk. Quick Start The repository uses the Cargo build tool. The compatibility between dependencies has been tested for Rust version 1.63. Build the repository using the following command. $ cargo build --release Next, generate configuration files for nodes in the system using the following command. $ ./target/release/genconfig --base_port 8500 --client_base_port 7000 --client_run_port 9000 --NumNodes 4 --blocksize 100 --delay 100 --target testdata/hyb_4/ --local true After generating the configuration files, run the script appxcon-test.sh in the scripts folder with the following command line arguments. This command starts Delphi with four nodes. $ ./scripts/appxcon-test.sh {epsilon} {rho} {Delta} testdata/hyb_4/syncer Substitute desired values of $\epsilon,\rho_0,\Delta$. Example values include $\epsilon=1,\rho_0=10,\Delta=100000$. The script randomly assigns input values $v_i$ to each node. This logic can be changed to make nodes start with custom input values. The outputs are logged into the syncer.log file in logs directory. The outputs of each node are printed in a JSON format, along with the amount of time the node took to terminate the protocol. Running the FIN ACS protocol requires additional configuration. FIN uses BLS threshold signatures to generate common coins necessary for proposal election and Binary Byzantine Agreement. This setup includes a master public key in the pub file, $n$ partial secret keys (one for each node) as sec0,...,sec3 files, and the $n$ partial public keys as `pub0,...,pub3` files. We utilized the crypto_blstrs library in the apss repository to generate these keys. Running in AWS We utilize the code in the Narwhal repository to execute code in AWS. This repository uses fabric to spawn AWS instances, install Rust, and build the repository on individual machines. Please refer to the benchmark directory for more instructions. System architecture Each node runs as an independent process, which communicates with other nodes through sockets. Apart from the $n$ nodes running the protocol, the system also spawns a process called syncer. The syncer is responsible for measuring latency of completion. It reliably measures the system's latency by issuing START and STOP commands to all nodes. The nodes begin executing the protocol only after the syncer verifies that all nodes are online, and issues the START command by sending a message to all nodes. Further, the nodes send a TERMINATED message to the syncer once they terminate the protocol. The syncer records both start and termination times of all processes, which allows it to accurately measure the latency of each protocol. Reproducing results in the paper The paper submitted to DSN'24 contains four plots with details about the termination latencies of Delphi, FIN, and Abraham et al.'s AAA protocol on a set of inputs. These experiments were conducted in two testbeds: (a) A geo-distributed testbed on Amazon Web Services (AWS) EC2 instances with upto 160 instances spanning 8 AWS regions around the world, and (b) A distributed testbed of Raspberry Pi devices deployed in a laboratory environment at Purdue University. The evaluation results on AWS can be reproduced by following the instructions in the README.md file in the benchmark directory of the extracted tar.gz file attached to this artifact. These results include the termination latency and network bandwidth utilized by each of the three protocols. However, reproducing the evaluation on the Raspberry Pi testbed requires the testbed to be online. We only turn this testbed on when someone wants access to it and switch it off at all other times to conserve energy. Further, the user willing to access this testbed would require SSH access to these machines. Anyone willing to reproduce these results on this testbed can contact Akhil Bandarupalli at abandaru@purdue.edu.