[MarkSweep]

There are all kinds of things subject to export restrictions:

https://www.bis.doc.gov/index.php/regulations/export-adminis...

For example, high resolution analog to digital converters have restrictions. In the past strong cryptography even had restrictions:

https://en.wikipedia.org/wiki/Export_of_cryptography_from_th...

Even travel for US citizens was restricted. I have relatives who were in the semiconductor and aerospace industries during the 1980s. They were advised by the government to not attempt to travel to the Eastern Bloc. Some kinda related reading:

https://academic.oup.com/dh/article-abstract/43/1/57/5068654...

[LionTamer]

I knew about the previous cryptography restrictions, but I also knew that the Supreme Court overruled them by ruling (as I understand it) that “code is speech”. I’ll have to check out the other links though

[schoen]

Not the Supreme Court, the Ninth Circuit in a subsequently-withdrawn opinion.

https://en.wikipedia.org/wiki/Bernstein_v._United_States

(Because the opinion was withdrawn, it's "persuasive" but not "binding".)

[LionTamer]

Good catch

[tankenmate]

This brings back memories of a t-shirt I had that had big red letters on it "Export Controlled" and an implementation of RSA in perl on it.

[Theodores]

    #!/usr/local/bin/perl -s-- -export-a-crypto-sardine -RSA-6-line-PERL-fish
    '\~.         __......--------~~~~~~~~~~~~~~~~~~~~~~~~-------....____
     \  ~.__---~';($k,$n)=@ARGV;$m=unpack(H.$w,$m."\0"x$w),$_=`echo  "[o~~-._
      \  ]s!16do$w 2+4Oi0$d*-^1[d2%Sa2/d0<X+d*La1=z\U$n%0]SX$k"[$m*]"\E[     ~.
      /  ]s!szlXx++p"|dc`,s/^.|\W//g,print pack('H*',$_)while read(STDIN,$m," .'
     /  .-~~--.._" +($w=2*$d-1+length($n||die"$0 [-d] k n\n")&~1)/2);'  __..-~
    ,/.~         ~~~~----........._______________________.......-----~~'