Validation of Bitcoin native data availability in ultra-low latency L2 environments @megaeth , @risechain , @nubit_org In blockchain, the term ultra-low latency or real-time goes beyond simply meaning a fast perceived speed; it refers to a structure that consistently provides execution, response, and state reflection faster than human cognitive limits. Recently emerged high-performance layer 2 systems are designed with execution delays in the millisecond range and very high throughput, and in this process, separating the execution layer from the validation layer has become common. In such environments, data availability serves as a foundational role that allows anyone to validate state transitions later, rather than being a direct factor that influences speed. Real-time L2 systems use techniques to pre-execute transactions before they are fully included in a block or to divide blocks into very small units to finalize the order. As a result, users can see almost immediate results, but cryptographically complete validation occurs much later. In this structure, the data availability layer must ensure that sufficient data is made public within a certain timeframe to allow for validation, and if delays or concealment occur, participants in the system are left with no choice but to trust the honesty of the sequencer during that period. Bitcoin native data availability is an approach that aims to provide this validation function directly relying on the Bitcoin blockchain. Bitcoin blocks are generated approximately every 10 minutes, and the data capacity that can be contained in a block is limited. This structure offers high economic security and strong censorship resistance, but it has a clear upper limit in terms of data posting frequency and throughput. As a result, data availability based on Bitcoin assumes a throughput of several kilobytes per second and a confirmation delay of at least several minutes. In real-time L2 environments, while execution delays are only a few milliseconds, if data availability confirmation takes several minutes, the time gap between execution and validation becomes extremely wide. During this gap, users cannot independently verify the state or safely recover assets, nor can they immediately confirm whether the data has actually been posted. This means that the intended effect of minimizing trust based on validation by the data availability layer is significantly delayed. Systems that implement Bitcoin native data availability use auxiliary mechanisms such as committee consensus, data sampling, and periodic Bitcoin anchoring to mitigate these limitations. However, unless the processing speed and block generation cycle of Bitcoin itself are changed, these methods do not provide the short validation delays required by real-time execution environments. The fact remains that at least one block's worth of time is needed to definitively judge and respond to data concealment or delays on-chain. This characteristic becomes even more apparent in applications that are extremely sensitive to delays, such as high-frequency trading or real-time gaming. In environments where a large number of transactions occur in a short time, Bitcoin block space cannot accommodate the demand for data availability, and validation delays also hinder the normal operation of applications. In contrast, in applications where transaction frequency is relatively low and the security of final settlement is more important, Bitcoin-based data availability can play a certain role. In summary, in ultra-low latency L2 environments, Bitcoin native data availability has structural limitations of validation delays and throughput constraints. While Bitcoin provides strong security and reliability, due to its design characteristics, it is not suitable for use as a data availability layer based on real-time execution. The current objective analysis confirms that in real-time L2 systems, Bitcoin native data availability functions more as a slow but highly secure auxiliary benchmark rather than as the primary validation means supporting execution.