Representative embodiments set forth herein disclose techniques for modifying encryption classes of files. According to some embodiments, a technique can include receiving a request to update an encryption configuration of a file from a current encryption class to an updated encryption class. In response, the technique involves obtaining (i) a first class key associated with the current encryption class, and (ii) a second class key associated with the updated encryption class. Next, the technique involves identifying file extents of the file, where each file extent is encrypted by a respective extent key that is encrypted by the first class key. Finally, the technique involves, for each file extent of the file: (i) decrypting the respective extent key using the first class key to produce a decrypted respective extent key, and (ii) encrypting the decrypted respective extent key using the second class key to produce an updated respective extent key.