> A mixture of pine rosin and beeswax known as "sealing wax" played an important part in 12th through 19th-century information security and 19th-century high-vacuum apparatus.

I suspect you are referring to a different use of rosin and beeswax, but the mixture was used for centuries for sealing - which is for information security. It was mixed with either arsenic-based or copper-based minerals to both color it, and protect it from slow fungal attack, so seals (after about a century of colorful failures) were always red or green.

A slightly different proportion was used as "code" (no relation to cyphers), a shoemaker's waterproofing glue for seams. AFAIK no coloring was added.