The unpredictability of transaction costs is another problem with the utilization of public blockchains in enterprise applications. This derives from the fact that transaction fees are used to allocate the resources of traditional blockchain networks (i.e., the computing power of miners) across users' transactions, while protecting against DOS attacks by imposing an economical barrier. Miners, by nature of performing the work, can choose which transactions they want to include in a block. As a result, users choose to pay higher miner rewards (in the form of gas costs) per transaction, so that their transactions are prioritized. This creates a feedback loop whereby, in periods of higher network activity, gas costs grow dramatically and unpredictably.