A fiber, a single filament of natural material, such as cotton, linen or wool, or artificial material such as nylon, polyester, metal or mineral fiber, or man made natural fibre like Viscose, Modal & Excel is measured in terms of linear mass density, the weight of a given length of fiber.
The vernam cipher, sometimes known as the 'one time pad', is a stream cipher, which providing certain requirements are met, can be theoretically unbreakable.
VTAM (Virtual Telecommunications Access Method) Also ACF/VTAM (Advanced Communications Function/VTAM), it is software that controls communications in an IBM SNA environment. VTAM usually resides in the mainframe under MVS or VM, but may be offloaded into a front end processor that is tightly coupled to the mainframe. It supports a wide variety of network protocols, including SDLC and Token Ring. VTAM can be thought of as the network operating system of SNA.