Such an attack involves a single entity or collusion among entities controlling more than half of the network's mining power, enabling them to manipulate the Median Time Past (MTP) by selectively ignoring blocks from other miners. This capability would theoretically allow these entities to maximize their profits at the expense of the network's credibility and the coin's value. However, the economic disincentive linked to the depreciation of mining equipment and the overall devaluation of the coin serves as a deterrent against such actions. In contrast, testnets, which lack a profit motive, may be more vulnerable to attacks carried out for experimental or disruptive purposes.

The discussion transitions into exploring theoretical solutions aimed at mitigating these risks without precipitating adverse outcomes within the digital currency ecosystem. Among the proposed measures, a range of modifications to time-related rules within the mining algorithm are considered, each varying in terms of perfection and feasibility. These include implementing a monotonic, approximately 10-second "arrival" rule alongside the elimination of the MTP, Future Time Limit (FTL), and existing constraints on block time adjustments (referred to as 4x and 1/4 limits). A less ideal but still effective approach suggests maintaining monotonicity while reducing the FTL and removing the MTP and aforementioned limits. As safer alternatives, setting a two-hour past time limit for every block or every 2016 blocks with enforced actual time adjustments emerges as practical options that balance security with operational simplicity.

Further complexity is added by the consideration of soft versus hard forks as mechanisms for introducing these changes. Hard forks, requiring widespread consensus among network participants, present a higher barrier to implementation compared to soft forks, which can be activated with support from a smaller segment of the network. The proposition of a one-day past time limit via a soft fork, advocated by Johnson Lau, illustrates a strategic compromise that aims to safeguard against prolonged >50% attacks with minimal disruption. This approach notably includes additional safeguards during the transition between mining difficulty adjustments, ensuring continuity and stability within the blockchain infrastructure.

By carefully weighing these theoretical interventions against their potential impacts on the cryptocurrency landscape, the conversation underscores the delicate balance between innovation, security, and the preservation of trust within digital economies.