conference paper published yes Ray Neiheiser author f09651b9-fec0-11ec-b5d8-934aff0e52a40000-0001-7227-8309 Eleftherios Kokoris Kogias author f5983044-d7ef-11ea-ac6d-fd1430a26d300000-0002-8827-3382 KrPi department FC: Financial Cryptography and Data Security Interface Theory for Security and Privacy project SeCure, privAte, and interoperabLe layEr 2 project Many blockchains such as Ethereum execute all incoming transactions sequentially significantly limiting the potential throughput. A common approach to scale execution is parallel execution engines that fully utilize modern multi-core architectures. Parallel execution is then either done optimistically, by executing transactions in parallel and detecting conflicts on the fly, or guided, by requiring exhaustive client transaction hints and scheduling transactions accordingly. However, recent studies have shown that the performance of parallel execution engines depends on the nature of the underlying workload. In fact, in some cases, only a 60% speed-up compared to sequential execution could be obtained. This is the case, as transactions that access the same resources must be executed sequentially. For example, if 10% of the transactions in a block access the same resource, the execution cannot meaningfully scale beyond 10 cores. Therefore, a single popular application can bottleneck the execution and limit the potential throughput. In this paper, we introduce Anthemius, a block construction algorithm that optimizes parallel transaction execution throughput. We evaluate Anthemius exhaustively under a range of workloads, and show that Anthemius enables the underlying parallel execution engine to process over twice as many transactions. Springer Nature2026Miyakojima, Japan eng 0302-9743 1611-3349 9783032070234 2502.1007410.1007/978-3-032-07024-1_18 15751307-323 Neiheiser R, Kokoris Kogias E. 2026. Anthemius: Efficient and modular block assembly for concurrent execution. 29th International Conference on Financial Cryptography and Data Security. FC: Financial Cryptography and Data Security, LNCS, vol. 15751, 307–323. Neiheiser, R., &#38; Kokoris Kogias, E. (2026). Anthemius: Efficient and modular block assembly for concurrent execution. In <i>29th International Conference on Financial Cryptography and Data Security</i> (Vol. 15751, pp. 307–323). Miyakojima, Japan: Springer Nature. <a href="https://doi.org/10.1007/978-3-032-07024-1_18">https://doi.org/10.1007/978-3-032-07024-1_18</a> Neiheiser R, Kokoris Kogias E. Anthemius: Efficient and modular block assembly for concurrent execution. In: <i>29th International Conference on Financial Cryptography and Data Security</i>. Vol 15751. Springer Nature; 2026:307-323. doi:<a href="https://doi.org/10.1007/978-3-032-07024-1_18">10.1007/978-3-032-07024-1_18</a> Neiheiser, Ray, and Eleftherios Kokoris Kogias. “Anthemius: Efficient and Modular Block Assembly for Concurrent Execution.” In <i>29th International Conference on Financial Cryptography and Data Security</i>, 15751:307–23. Springer Nature, 2026. <a href="https://doi.org/10.1007/978-3-032-07024-1_18">https://doi.org/10.1007/978-3-032-07024-1_18</a>. R. Neiheiser and E. Kokoris Kogias, “Anthemius: Efficient and modular block assembly for concurrent execution,” in <i>29th International Conference on Financial Cryptography and Data Security</i>, Miyakojima, Japan, 2026, vol. 15751, pp. 307–323. R. Neiheiser, E. Kokoris Kogias, in:, 29th International Conference on Financial Cryptography and Data Security, Springer Nature, 2026, pp. 307–323. Neiheiser, Ray, and Eleftherios Kokoris Kogias. “Anthemius: Efficient and Modular Block Assembly for Concurrent Execution.” <i>29th International Conference on Financial Cryptography and Data Security</i>, vol. 15751, Springer Nature, 2026, pp. 307–23, doi:<a href="https://doi.org/10.1007/978-3-032-07024-1_18">10.1007/978-3-032-07024-1_18</a>. 210422026-01-25T23:01:40Z2026-02-12T13:39:07Z