Regular Research Articles -- Unbounded Barrier-Synchronized Concurrent ASMs for Effective MapReduce Processing on Streams -- Towards ASM-based automated formal verification of security protocols -- Verifying System-level Security of a Smart Ballot Box -- Proving the safety of a Sliding Window Protocol with Event B -- Event-B formalization of Event-B contexts -- Validation of Formal Models by Timed Probabilistic Simulation -- Short Articles -- Sterling: A Web-based Visualizer for Relational Modeling Languages -- Extending ASMETA with time features -- About the Concolic Execution and Symbolic ASM Function Promotion in CASM -- Towards Refinement of Unbounded Parallelism in ASMs Using Concurrency and Reflection -- The CamilleX Framework for the Rodin Platform -- Extensible Record Structures in Event-B -- Formalizing and Analyzing System Requirements of Automatic Train Operation over ETCS using Event-B -- Automatic Transformation of SysML Model to Event-B Model for Railway CCS Application -- Short Articlesof the PhD-Symposium (Work in Progress) -- Formal Meta Engineering Event-B: Extension and Reasoning - The EB4EB Framework -- A modeling and verification framework for security protocols -- Formalizing the Institution for Event-B in the Coq Proof Assistant.

This book constitutes the proceedings of the 8th International Conference on Rigorous State-Based Methods, ABZ 2021, which was planned to take place in Ulm, Germany, during June 6-11, 2021. The conference changed to an online format due to the COVID-19 pandemic. The 6 full and 8 short papers included in this volume were carefully reviewed and selected from 18 submissions. The proceedings also include 3 PhD symposium contributions. They deal with state-based and machine-based formal methods, mainly Abstract State Machines (ASM), Alloy, B, TLA+, VDM, and Z. .