Scrambler and storage device using the same
A scrambler that facilitates encryption of data to be recorded and a magnetic storage device using this are provided. The scrambler has a shift register of a plurality of stages and an exclusive OR circuit that finds the exclusive OR of the logic of the stages of the shift register that correspond to a single generating polynomial. The output of the exclusive OR circuit is arranged to be fed back to the initial stage of the shift register. At least this single generating polynomial is an arbitrary generating polynomial. The drive number, in binary form, that identifies the storage device, is set as the initial value of the shift register of a plurality of stages.
1 . A scrambler comprising:
a shift register of a plurality of stages; and
an exclusive OR circuit for finding the exclusive OR of the logic of stages of said shift register corresponding to a single generating polynomial,
output of said exclusive OR circuit being fed back to the initial stage of said shift register, and at least one of said generating polynomial and the initial value set in said shift register being arbitrarily set.
2 . The scrambler according to claim 1 , wherein an arbitrary initial value is set in said shift register.
3 . The scrambler according to claim 1 , wherein said one generating polynomial is an M sequence generating polynomial.
4 . The scrambler according to claim 2 , wherein said one generating polynomial is an M sequence generating polynomial.
5 . A scrambler for encryption of data on a storage device, comprising:
a shift register of a plurality of stages; and
an exclusive OR circuit for finding the exclusive OR of the logic of stages of said shift register corresponding to a single generating polynomial,
output of said exclusive OR circuit being fed back to the initial stage of said shift register, and at least said generating polynomial being an arbitrary generating polynomial,
as the initial value of said shift register of a plurality of stages, the binary number of at least one of the drive number identifying said storage device, the cylinder number, head number and sector number of said storage device, or the binary number of the exclusive OR of an arbitrary combination thereof being set.
6 . The scrambler according to claim 5 , wherein said one generating polynomial is an M sequence generating polynomial.
7 . A storage device for encrypting and recording input data, comprising:
a circuit that generates encrypted data by the exclusive OR of input data to be magnetically recorded and a scrambling signal scrambled by a scrambler; and
a control section that exercises control of recording of encrypted data from the circuit that generates said encrypted data onto a magnetic disk, wherein
said scrambler comprises:
a shift register of a plurality of stages; and
an exclusive OR circuit that finds the exclusive OR of the logic of stages of said shift register corresponding to one generating polynomial, and wherein
said scrambler is configured so that the output of said exclusive OR circuit is fed back to the initial stage of said shift register, and at least said one generating polynomial is an arbitrary polynomial, and wherein
as the initial value of said shift register of a plurality of stages, there is set the binary number of at least one of the cylinder number, head number and sector number of said storage device, or the binary number of the exclusive OR of an arbitrary combination thereof.
8 . The magnetic storage device according to claim 7 , wherein said one generating polynomial is an M sequence generating polynomial.
9 . A semiconductor integrated circuit comprising:
a shift register of a plurality of stages; and
an exclusive OR circuit for finding the exclusive OR of the logic of stages of said shift register corresponding to one generating polynomial,
further comprising a scrambler so that output of said exclusive OR circuit is fed back to the initial stage of said shift register, and at least one of said generating polynomial and the initial value set in said shift register is arbitrarily set.
10 . The semiconductor integrated circuit according to claim 9 , further comprising a recording circuit for signal processing to record a signal on a recording medium.