If I were to encrypt an existing text column in an oracle table and tried to query this column, would performance worsen?

For example if I had an encrypted column that is a Name field, and I wanted to search for the name John, would spring JPA have a significant performance impact from doing this rather than keeping the Name field unencrypted?

I was hoping to get an estimate of additional time the decryption takes and multiple that by the number of rows needed to be searched. I know it must depend on the algorithm but in the best case scenario how much longer would it take to decrypt just a cell?