密钥 is a technical term in cryptography referring to cryptographic keys used to encrypt and decrypt messages, (and sign and verify, but that's whole another story)
Given that a physical door key or a safe box key is often used as metaphore when explaining a cryptographic key, the 钥 in 密钥 should corresponds to 钥匙, which is pronounced as yàoshì, by this logic, it should probably be pronounced as mìyào. However, my collegues from financial department says the government clerks they communicate with pronounce it as yuè and 密钥 as mìyuè.
So by the end of day, how should 密钥 be pronounced? And why?