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.
cipher. Any cryptographic system in which arbitrary symbols (or groups of symbols) represent units of plain text of regular length, usually single letters; units of plain text are rearranged; or both, in accordance with certain predetermined rules.