The FromFile method imports the contents of a file into the
memory Blob. You can use this method to make a Blob read a
file, and later encrypt, digest or sign it using the wodCrypt
component.
If you work with large files, you might prefer to use the
FileBlob object
instead. This way the contents of the file will never be moved into
memory all at once. It will be read/written partially, as
needed by wodCrypt.