A technique includes performing element-by-element encryption of a segment of the plaintext string to provide a segment of an encrypted string. Performing the element-by-element encryption includes, for a given string element of the segment of the plaintext string, encrypting the given string element to provide a given string element of the segment of the encrypted string; and tweaking the encryption of the given string element based on a selector that includes multiple string elements of the encrypted string. The technique may include searching an encrypted database based on the encrypted string.