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.
Definition of cipher. 1a : zero 1ab : one that has no weight, worth, or influence : nonentity She was nothing more than a cipher. 2a : a method of transforming a text in order to conceal its meaning secret communications written in cipher â compare code 3bb : a message in code The cipher cannot be decoded without the key. 3 : arabic numeral.