公开(公告)号：JP2001325152A

公开(公告)日：2001-11-22

申请号：JP2001078856

申请日：2001-03-19

Applicant: IBM

Inventor： INCERTIS CARRO FERNANDO ,  MATYAS STEPHEN

IPC: G06F12/14 ,  G06F17/21 ,  G06F17/22 ,  G06F21/64 ,  G09C1/00 ,  G09C5/00 ,  H04N1/32

Abstract: PROBLEM TO BE SOLVED: To provide a method for merging information required for authenticating a text document to a main body of the document in a form of an excess blank between words. SOLUTION: This method for marking an original text document by changing existing blank characters among words is disclosed. First, intervals among words are made to be composed only of the odd numbers of blank characters by applying reversible deformation. Next, an authentication pattern is merged to a first subset by dividing a deformed original text into two subsets and adding the blank characters among words to them. An ambiguous pattern for further changing the number of blank characters is calculated for concealing the authentication pattern. An text with mark to be authenticated is obtained by combining both subsets again after making a second subset ambiguous as well. In addition, a method for authenticating the text document marked according to the above method is also disclosed.

公开(公告)号：IT1163746B

公开(公告)日：1987-04-08

申请号：IT2824779

申请日：1979-12-20

Applicant: IBM

Inventor： MATYAS STEPHEN ,  MEYER CARL HEINZ WILHELM ,  TUCKERMAN LOUIS BRYANT

IPC: E05B49/00 ,  G09C1/06 ,  H04K1/00 ,  H04L9/06 ,  H04L9/14 ,  G06K

公开(公告)号：AT359563T

公开(公告)日：2007-05-15

申请号：AT01480017

申请日：2001-02-27

Applicant: IBM

Inventor： INCERTIS CARRO FERNANDO ,  MATYAS STEPHEN

IPC: G06F12/14 ,  G06F17/21 ,  G06F17/22 ,  G06F21/64 ,  G09C1/00 ,  G09C5/00 ,  H04N1/32 ,  G06F21/00

Abstract: A method of marking an original text document in which existing inter-word blank characters are altered is disclosed. A reversible transform is first applied so that inter-word intervals become exclusively comprised of odd numbers of blank characters. Transformed original text is then split in two subsets and an authentication pattern is merged into first subset by adding inter-word blank characters. A blurring pattern is computed which further modify the number of blank characters so as to hide the authentication pattern. Second subset is blurred too before subsets are recombined to obtain a marked text susceptible of authentication. A method of authenticating a text document marked according to the here above method is also disclosed. The system and the methods of the invention permit that a text document be authenticable while authentication pattern is imbedded, and deeply hidden, into the text document itself. Also, the exact original format, including the numbers of inter-word blanks, can be restored by the recipient.

公开(公告)号：DE60127747T2

公开(公告)日：2008-01-24

申请号：DE60127747

申请日：2001-02-27

Applicant: IBM

Inventor： INCERTIS CARRO FERNANDO ,  MATYAS STEPHEN

IPC: G06F12/14 ,  G06F17/21 ,  G06F17/22 ,  G06F21/64 ,  G09C1/00 ,  G09C5/00 ,  H04N1/32

Abstract: A method of marking an original text document in which existing inter-word blank characters are altered is disclosed. A reversible transform is first applied so that inter-word intervals become exclusively comprised of odd numbers of blank characters. Transformed original text is then split in two subsets and an authentication pattern is merged into first subset by adding inter-word blank characters. A blurring pattern is computed which further modify the number of blank characters so as to hide the authentication pattern. Second subset is blurred too before subsets are recombined to obtain a marked text susceptible of authentication. A method of authenticating a text document marked according to the here above method is also disclosed. The system and the methods of the invention permit that a text document be authenticable while authentication pattern is imbedded, and deeply hidden, into the text document itself. Also, the exact original format, including the numbers of inter-word blanks, can be restored by the recipient.

公开(公告)号：DE60127747D1

公开(公告)日：2007-05-24

申请号：DE60127747

申请日：2001-02-27

Applicant: IBM

Inventor： INCERTIS CARRO FERNANDO ,  MATYAS STEPHEN

IPC: G06F12/14 ,  G06F17/21 ,  G06F17/22 ,  G06F21/64 ,  G09C1/00 ,  G09C5/00 ,  H04N1/32

Abstract: A method of marking an original text document in which existing inter-word blank characters are altered is disclosed. A reversible transform is first applied so that inter-word intervals become exclusively comprised of odd numbers of blank characters. Transformed original text is then split in two subsets and an authentication pattern is merged into first subset by adding inter-word blank characters. A blurring pattern is computed which further modify the number of blank characters so as to hide the authentication pattern. Second subset is blurred too before subsets are recombined to obtain a marked text susceptible of authentication. A method of authenticating a text document marked according to the here above method is also disclosed. The system and the methods of the invention permit that a text document be authenticable while authentication pattern is imbedded, and deeply hidden, into the text document itself. Also, the exact original format, including the numbers of inter-word blanks, can be restored by the recipient.

公开(公告)号：FR2808948B1

公开(公告)日：2006-03-03

申请号：FR0104303

申请日：2001-03-30

Applicant: IBM CORP INTERNAT BUSINESS MAC

Inventor： INCERTIS CARRO FERNANDO ,  MATYAS STEPHEN

IPC: H04L9/32 ,  G06F17/22 ,  G06F21/64 ,  G06T1/00 ,  H04L29/06 ,  H04N1/32

Abstract: A system and method for unique authentication of each replication of a plurality of soft-copy documents, forming a group. One soft-copy document, out of the group, becomes a carrier for an authentication code aimed at protecting the group. The authentication code is computed from the concatenation of the plurality of soft-copy documents and a key. A random number is also generated for each replication of the group of files. The random number is combined with the authentication code to mark the soft-copy document which has been selected to become the carrier. Thus, the invention introduces randomization in the insertion of the authentication code so that for each replication of an identical group of data files, unique authentication data can be associated, merged and hidden in the transmitted information.

公开(公告)号：FR2808948A1

公开(公告)日：2001-11-16

申请号：FR0104303

申请日：2001-03-30

Applicant: IBM CORP INTERNAT BUSINESS MAC

Inventor： INCERTIS CARRO FERNANDO ,  MATYAS STEPHEN

IPC: G06F17/22 ,  G06F21/64 ,  G06T1/00 ,  H04L9/32 ,  H04L29/06 ,  H04N1/32

Abstract: A system and method for unique authentication of each replication of a plurality of soft-copy documents, forming a group. One soft-copy document, out of the group, becomes a carrier for an authentication code aimed at protecting the group. The authentication code is computed from the concatenation of the plurality of soft-copy documents and a key. A random number is also generated for each replication of the group of files. The random number is combined with the authentication code to mark the soft-copy document which has been selected to become the carrier. Thus, the invention introduces randomization in the insertion of the authentication code so that for each replication of an identical group of data files, unique authentication data can be associated, merged and hidden in the transmitted information.