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Data Protection Method of Prediction Coding Scheme with Password

IP.com Disclosure Number: IPCOM000114056D
Original Publication Date: 1994-Nov-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 4 page(s) / 80K

Publishing Venue

IBM

Related People

Maezawa, Y: AUTHOR [+2]

Abstract

Password information is utilized as the first reference information for a prediction coding scheme. The prediction coding scheme predicts a current information unit by reference of a previous information unit and encodes the prediction errors in an information unit. A conventional prediction method assumes the first reference information unit which is outside of the information to be coded is all certain value such as all white ("0"). This new data protection method puts a password to the first reference information unit and encodes the first current information unit by reference of the password. The password input to the first reference unit is required to decode the encoded data correctly so the password can protect the encoded data.

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Data Protection Method of Prediction Coding Scheme with Password

      Password information is utilized as the first reference
information for a prediction coding scheme.  The prediction coding
scheme predicts a current information unit by reference of a previous
information unit and encodes the prediction errors in an information
unit.  A conventional prediction method assumes the first reference
information unit which is outside of the information to be coded is
all certain value such as all white ("0").  This new data protection
method puts a password to the first reference information unit and
encodes the first current information unit by reference of the
password.  The password input to the first reference unit is required
to decode the encoded data correctly so the password can protect the
encoded data.

The subject new data protection method is explained in more detail
using following figures.
  1.  The information unit 1 (abbreviated as IU-1 hereinafter) is
       predicted by reference of the previous IU which is the
reference
       IU-0 as shown in Fig. 1.
  2.  Password is stored to the reference IU-0 so the IU-1 is
predicted
       in reference with the password.  The reference IU-0 used to be
       pseudo values such as all "0".
  3.  The prediction of the IU-1 with the IU-0 produces a prediction
       error information unit-1 as shown in Fig. 2.
  4.  The prediction error IU is coded with Huffman codes.
  5.  A general equation of the coding method is indicated as
follows:
               Huffman code(Prediction (IU-(n-1)) EOR IU-n)
               Where n=1 to Last
                    IU-0 is password IU.
               Note: EOR means Exclusive OR.
          Fig. 3 shows a c...