By classifying it as a munition and using those laws. Which don't apply to books like "Applied Cryptography" by Bruce Schneier, due to the First Amendment. Even if they have source code printed in their appendices.
Oh, you mean effectively? Uh... I suppose we'll have to get back to you on that.
Back in the day, someone printed up a T-shirt that had a 4-line Perl script that did RSA and so was a munition. (Later reduced to 3 lines.) There was a barcode that contained the bits for the script, which you could use to automatically read the program into a properly configured computer, so the T-Shirt was indeed a munition under those regulations.
By classifying it as a munition and using those laws. Which don't apply to books like "Applied Cryptography" by Bruce Schneier, due to the First Amendment. Even if they have source code printed in their appendices.
Oh, you mean effectively? Uh... I suppose we'll have to get back to you on that.