> The question has moved from "should it be secret" to "how long must it be secret?" because the longer you need to keep it secret, the more computationally exp

> The question has moved from "should it be secret" to "how long must it be secret?" because the longer you need to keep it secret, the more computationally expensive the encryption is going to be. To be fair, encryption strenght has always been rated on the basis of how long it should stay secret. For example a site like https://www.keylength.com/en/compare/ https://www.keylength.com/en/compare/ (which has been around a very long time) guides you to pick key strenght based on how many years you'd want the data to be protected.