Strong cryptography tattoos were the bump stocks of the 1990's:
"Richard White <[email protected]> had his wife (who is a tattoo artist) put a tattoo of [RSA encryption] on his forearm.
Gif of the Richard's tattoo now available here:
https://imgur.com/xKupqeG
This means that he may, technically, qualify as a munitions on the USML, and as a result not be allowed to show the tattoo to a foreign national in the US, nor leave the US."
http://cypherpunks.venona.com/date/1995/12/msg00332.html
"Richard White <[email protected]> had his wife (who is a tattoo artist) put a tattoo of [RSA encryption] on his forearm.
Gif of the Richard's tattoo now available here:
https://imgur.com/xKupqeG
This means that he may, technically, qualify as a munitions on the USML, and as a result not be allowed to show the tattoo to a foreign national in the US, nor leave the US."
http://cypherpunks.venona.com/date/1995/12/msg00332.html