Concrete v2.4.0: Multi-Parameter Optimization and More Accurate Bitwidth

Since the release of Concrete v2.0.0 in July 2023, four minor updates have been introduced, enhancing performance, adding new features, and fixing bugs. A major improvement is the multi-parameter optimization, which uses several key-switching and bootstrapping keys to improve the efficiency and latency of Fully Homomorphic Encryption (FHE) evaluations. This optimization, active by default from version 2.1.0, has improved the speed of various operators. The updates also include the provision of detailed statistics for developers, offering insights into cryptographic operations to facilitate better program optimization. Additionally, a new feature enables dynamic table lookups, allowing computations with tables determined at execution time. These enhancements, alongside other minor improvements, have significantly boosted the performance of Concrete, as evidenced by benchmarks like CIFAR, which now run markedly faster.