You may be interested in bsdiff[0] or Courgette[1]. If the file is a new version of what you deployed previously, you can use these programs to produce binary patch files. Diff the old and new binaries, and you'll only need to transmit the patch.

bsdiff is a generic binary differ that is widely available. Courgette is optimized for executables and has an uncommon build system, but claims to produce files ~85% smaller than bsdiff.

[0] https://www.daemonology.net/bsdiff/

[1] https://www.chromium.org/developers/design-documents/softwar...