I think the process is called EFS and in most cases the encryption of the key used to encrypt the file by an asymmetric cipher but what I don't understand is how exactly the files are encrypted.

Now I'm not referring to text files specifically so it can be apps and such too so what does the encryption process actually work on? Can it access the source code for the files and encrypt that (but I don't think this is the case since the source code for most files isn't freely available) or does it just encrypt the file names (but still this would be easy to brute force through given that most filenames are short and names of extensions are limited)?

  • Could you please elaborate? Any specific type of encryption? Feb 3, 2020 at 17:45
  • What do you mean by the source code of the files? May 10, 2021 at 19:29

1 Answer 1


No, the actual file data is encrypted for EFS. For this the system that performs the encryption needs to be able to access the data. If a full file system offers encryption then you do generally need system level access to setup encryption.

Modern encryption act on bits & bytes. The type of file doesn't matter for the encryption procedure; it just acts on the bytes.

Encryption of filenames doesn't offer much protection; it depends on the level of encryption if the file names are encrypted at all. If you encrypt a single file then you must be able to find it back after all.

If you encrypt a complete filesystem then all logical sectors that make up the file system are encrypted and this will include the file names and any other meta-data.

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