Security teams are torn between the quest to encrypt everything and the technical feasibility of doing so. The advantage of encryption is that it obscures data, even after a breach, and satisfies privacy regulations. But it can also obstruct application performance, especially when applied to data in cloud services. Regular encryption should be used for any data that requires the highest security, even at the price of losing search and other functionality. Regular symmetric key encryption hides all useful information about the data: the key, the message, any bit of the message.”]
Source: https://www.darkreading.com/cloud/there-s-no-one-perfect-method-for-encryption-in-the-cloud