  Blockchains like Bitcoin and Ethereum have revolutionized digital
transactions, yet scalability issues persist. Layer 2 solutions, such as
validity proof Rollups (ZK-Rollups), aim to address these challenges by
processing transactions off-chain and validating them on the main chain.
However, concerns remain about security and censorship resistance, particularly
regarding centralized control in Layer 2 and inadequate mechanisms for
enforcing these properties through Layer 1 contracts. This work presents a
formal analysis using the Alloy specification language to examine and design
key Layer 2 functionalities, including forced transaction queues, safe
blacklisting, and upgradeability. Through this analysis, we identify potential
vulnerabilities in current mechanisms and propose enhanced models to strengthen
security and censorship resistance, setting new standards for the security of
rollups.
