What is the BEAST90 protocol?

Could you please clarify what the BEAST90 protocol entails? I'm curious to know if it's a recently developed cryptographic standard or an older method that's still relevant in the world of cryptocurrency and finance. Could you elaborate on its primary functions and how it contributes to the security and efficiency of transactions within this industry? Furthermore, is it widely adopted by cryptocurrency exchanges and platforms, or is it a niche protocol used by specific entities? Lastly, what are some potential drawbacks or limitations associated with the BEAST90 protocol that practitioners in the field should be aware of?