In recent years, the use of salt caverns for hydrogen storage has gained increasing attention as a promising solution for supporting the global transition toward a carbon-neutral economy. This approach is seen as essential for achieving net-zero emissions and facilitating the move toward a sustainable energy future. The geological properties of salt caverns make them particularly suitable for this purpose due to their low permeability and high injection-withdrawal cycle frequency, which are ideal for safely storing hydrogen gas. Despite these advantages, several challenges remain, particularly related to the interaction between salt rocks and high salinity brines, which can lead to structural weakening. In this study, we investigated the factors that contribute to the weakening and cracking of salt rock when exposed to high salinity brine. Through a series of experiments using brine with salinities of 0 ppm, 50,000 ppm, 150,000 ppm, and 250,000 ppm, and salt rock samples containing halite, calcite, dolomite, quartz, and K-feldspar, we observed that prolonged exposure to brine can lead to the formation of oversized pores, up to 50 μm in diameter, on the surface of the salt rock. These enlarged pores can compromise the structural integrity of the rock, leading to increased permeability and potential failure of the storage system. Our analysis suggests that the primary mechanisms driving this damage are: (1) the combined dissolution and detachment of halite crystals embedded within the salt rock, and (2) the similar dissolution and detachment of calcite and dolomite grains, which are present as impurities. These processes lead to significant changes in the rock's microstructure, contributing to its overall deterioration. Additionally, we developed a novel methodology to accurately measure the permeability and porosity of salt rocks under hydrogen gas flow. This new approach employs modified boundary conditions, differing from the conventional Pressure Pulse Decay (PPD) method. In the PPD method, permeability is determined by creating a pressure gradient across the core, which can result in overestimated permeability due to hydrogen leakage through the sleeve and the sleeve-rock interface. By contrast, our method involves applying identical negative pressure pulses at both ends of the sample. This allows the gas, initially at higher pressure within the sample, to flow toward both ends through the pore spaces of the rock, which minimizes the possibility of leakage. The novel technique offers improvements in measurement accuracy, reducing errors by at least tenfold. Additionally, it significantly shortens the measurement time it by a factor of at least four compared to PPD method. Our results indicate that the measured permeability values for salt rocks fall within the nano-darcy range, with the porosity values below 5%. However, this study also highlighted the presence of slippage effect during hydrogen flow through salt rock samples. during hydrogen flow through salt rock samples. The slippage effect, or Klinkenberg effect, occurs when the gas molecules are more frequently interacting with the pore walls than with each other. This happens when the mean free path of the gas molecules (the distance a molecule travels before colliding with another molecule) becomes comparable to or larger than the size of the pores in the rock. In such cases, the gas flow is dominated by collisions between the gas molecules and the pore walls, rather than collisions between the gas molecules themselves. This interaction results in an apparent increase in permeability, as the gas can flow more easily through the rock compared to Darcy flow, where molecular collisions dominate. Our results show that sample #1 exhibited an intrinsic permeability of 3.47 nD and a Klinkenberg coefficient of 4.05 MPa, sample #2 showed 17.265 nD and 1.89 MPa, and sample #3 had 3.14 nD and 2.22 MPa. Additionally, the porosity of the samples was generally below 5%, measured at 2.7%, 3.2%, and 1.5% for sample 1 to 3, respectively. As a result, we determined that the permeability measurements must be corrected for the slippage effect to accurately reflect the intrinsic permeability of the salt rock, which is critical for reliable predictions of hydrogen containment and long-term cavern stability.