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.
A. DES carries out 16 rounds of mathematical computation on each 64-bit block of data it is responsible for encrypting. A round is a set of mathematical formulas used for encryption and decryption processes.