Could you elaborate on the process of selling cryptocurrencies on Bifrost? As a novice trader, I'm curious about the steps involved in listing my assets for sale on this platform. Specifically, I'd like to know about the necessary preparations, such as ensuring my account is verified and funded. Additionally, I'm interested in understanding the process of placing an order, including the various order types and how they differ. Also, how secure is the trading environment on Bifrost, and are there any safety measures I should take while selling? Finally, could you provide an estimate of the typical transaction time and any associated fees I might encounter?