What is the cost of protocol?

Could you please elaborate on the question "What is the cost of protocol?"? Are you inquiring about the financial cost associated with developing or implementing a specific cryptographic protocol? Or are you referring to the transactional costs incurred when using a blockchain-based protocol for transactions? It's important to clarify, as the cost of a protocol can vary depending on its intended use, the complexity of its implementation, and the underlying technology it's built upon. Could you provide more context or specify your question further? This would help me to give you a more accurate and relevant answer.