The definition of munitions includes weapons but is not restricted solely to weapons. From dictionary.com:
noun
Usually, munitions. materials used in war, especially weapons and ammunition.
material or equipment for carrying on any undertaking.
verb (used with object)
to provide with munitions.
Just because cryptographic technology is listed as a munition doesn't mean it's a weapon. Further, the list of restricted munitions is related to the definition created within the International Traffic in Arms Regulations (ITAR).
Part 21 of ITAR, the part that lists and defines munitions for purposes of the regulations, lists "cryptographic devices" under Category XIII - Materials and Miscellaneous Articles.
Further, Texas defines weapons, for purposes of a "Weapons Free School Zone", in Texas Penal Code, Title 10, Chapter 46. A "Weapons Free School Zone", by itself, doesn't prohibit weapons. It increases the penalty for committing an offense described in the above chapter.
Note: it may still be illegal to take a weapon into a "Weapons Free School Zone" depending on other statutes - both federal and local. However, the definition of the "Weapons Free School Zone" does not, by itself, prohibit the weapon.)
Summary:
- The definition of cryptographic equipment being a munition is one created as part of ITAR.
- A munition does not always mean weapon
- The definition of weapons for Texas "Weapons Free School Zones" is provided by Texas law, not federal law or regulation (ITAR)
- The application of the ITAR definition of munitions does not apply to the Texas "Weapons Free School Zones" law