Metadata Irreversible

One of the easiest ways to remove all metadata from a file, is by invoking ¹

 $ exiftool -all= <file>

However, this has the inconvenience of providing a security risk by reversing it as well with:

 $ exiftool -pdf-update:all= <file> 

which pretty much inserts the metadata back into the file:

According to the author of exiftool this can be circumvented by issuing qpdf --linearize <file.in> <file.out>. For further info about this see: PDF tags

References

exiftool man pages _↩︎