What is claimed is:
1. A method of marking an original text document 300, said original text document comprised of words 125 separated by inter-word intervals, said inter-word intervals including one 110 or more 115 blank characters, said method consisting in altering the numbers of said blank characters, said method comprising the steps of:
applying a reversible transform 305 over said original text document in order that all said inter-word intervals become exclusively comprised of odd numbers of said blank characters 425;
splitting 310 transformed said original text document into a first subset 520 and a second subset 530 of said words including the trailing said inter-word intervals of said words;
and, over said first subset:
computing 315, from said original text document and a secret-key 312, an authentication pattern 610 that fits the number of said intervals of said first subset;
adding 320 inter-word blank characters in positions corresponding to said authentication pattern;
generating 325 canonical form of said first subset;
computing 330, from said canonical form of said first subset and said secret-key, a blurring pattern 630 that fits the number of said intervals of said first subset;
modifying 335 the numbers of inter-word blank characters according to said blurring pattern;
and, over said second subset:
generating 345 canonical form of said second subset;
computing 350, from said canonical form of said second subset and said secret-key, a blurring pattern that fits the number of said intervals of said second subset;
modifying 355 the numbers of inter-word blank characters according to said blurring pattern;
recombining 340 said first subset and said second subset thereby, obtaining a marked text for authentication.
2. A method of authenticating a marked text document 700, said marked text document comprised of words 125 separated by inter-word intervals, said inter-word intervals including one 110 or more 115 blank characters, said method consisting in checking the numbers of said blank characters, said method comprising the steps of:
splitting said marked text document 710 into a first subset and a second subset of said words including the trailing said inter-word intervals of said words;
and, over said first subset:
generating 725 canonical form of said first subset;
computing 730, from said canonical form of said first subset and a secret-key 712, a blurring pattern that fits the number of said intervals of said first subset;
erasing 735 modifications brought to the numbers of said inter-word blank characters per said blurring pattern;
extracting 720 an authentication pattern thereby, obtaining in all said inter-word intervals odd numbers of blank characters;
and, over said second subset:
generating 745 canonical form of said second subset;
computing 750, from said canonical form of said second subset and said secret-key 712, a blurring pattern that fits the number of said intervals of said second subset;
erasing 755 modifications brought to the numbers of said inter-word blank characters per said blurring pattern thereby, obtaining in all said inter-word intervals odd numbers of blank characters;
recombining said first subset and said second subset;
applying a reverse transform 705 thus, retrieving said original text document;
computing 715, from retrieved said original text document and said secret-key 712, an authentication pattern that fits the number of said intervals of retrieved said original text document;
comparing 760 extracted said authentication pattern 720 and computed said authentication pattern 715;
if matching exactly:
accepting said marked text document as authentic;
if not:
rejecting said marked text document as fake.
3. The method of anyone of the previous claims wherein splitting steps 310 710 includes the preliminary steps of:
generating 302 702 a canonical form of a text document;
computing 307 707, from said canonical form of said text document and said secret-key, a splitting pattern 510 that fits the number of said intervals of said text document;
thereby, allowing to split and to recombine said text document 300 700 on the basis of asserted and non-asserted bits of said splitting pattern.
4. The method according to any one of the previous claims wherein said authentication pattern 610, said blurring pattern 630 and said splitting pattern 510 are binary vectors comprised of a number of bits matching the number of corresponding said inter-word intervals.
5. The method according to any one of the previous claims wherein said canonical form 120 is obtained in stripping all blank characters, in excess of one, off said inter-word intervals.
6. The method according to any one of the previous claims wherein modifying steps include:
in the positions corresponding to the asserted bits of said blurring patterns:
adding one blank character if said inter-word intervals are comprised of an odd number of said blank characters;
removing one blank character if said inter-word intervals are comprised of an even number of said blank characters.
7. The method according to any one of the previous claims wherein modifying steps and erasing steps perform identically.
8. The method according to any one of the previous claims wherein extracting step includes:
removing one blank character in those of said inter-word intervals that are comprised of an even number of said blank characters;
obtaining a binary authentication vector with asserted bits corresponding to positions where said blank characters were removed.
9. An authentication system, in particular a system for authenticating text document, comprising means adapted for carrying out the method according to any one of the previous claims.
10. A computer-like readable medium comprising instructions for carrying out the method according to any one of the claims 1 to 9.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A head substrate of a printing head capable of being detachably mounted on a printer main body, comprising:
plural external connection terminals for externally entering various signals and electric power;
recording means for recording according to the various signals;
data memory means to which data is written and from which data is read; and
memory access means for executing the data writing into said data memory means in response to signals entered via the external connection terminals and the electric power and for executing the data readout in response to other signals entered via the external connection terminals
wherein the head substrate is adapted so as to be capable of permanently disabling the data writing into said data memory means by said memory access means; by shutting off a supply of the electric power for data writing from said external connection terminals to said memory access means.
2. A head substrate according to claim 1, further comprising:
common terminal wiring means for connecting said memory access means and said recording means to a common external connection terminal.
3. A head substrate according to claim 1, wherein:
said external connection terminals receive, at one end thereof, from the exterior, an access permission signal for permitting the data writing; and
said memory access means executes data writing into said data memory means when the access permission signal is externally entered from said external connection terminal.
4. A head substrate according to claim 1, wherein:
said memory access means writes data of plural kinds in succession in said data memory means; and
said writing inhibition means individually disables data overwriting for the data of the plural kinds written in succession in said data memory means by said memory access means.
5. A head substrate according to claim 1, wherein:
said plural external connection terminals externally receive, as the various signals, a binary logic signal corresponding to whether or not to execute the recording, a recording image signal and a clock signal;
said recording means is adapted for executing a recording operation by externally receiving the recording image signal and the clock signal when the binary logic signal externally entered from the external connection terminals is in a first state; and
said memory access means is adapted for executing at least either of data writing into or data readout from said data memory means at a timing corresponding to the clock signal, when the binary logic signal externally entered into said external connection terminal is in a second state.
6. A head substrate according to claim 5, wherein the clock signal for executing the recording operation and the clock signal supplied to said memory access means are used in common.
7. A printing head capable of being detachably mounted in a printer main body, comprising a head substrate according to claim 5.
8. A printing apparatus comprising:
a printing bead according to claim 7;
wherein said recording input means is adapted for individually transmitting a binary logic signal of a second state and various signals such as a recording image signal and a recording clock signal respectively to a plurality of said external connection terminals of the printing head; and
said memory readout means is adapted for transmitting the binary logic signal of the second state and the memory clock signal, etc. to the plurality of said external connection terminals of the printing head.
9. A head substrate according to claim 1, wherein:
said recording means is adapted for recording based on the recording image signal serially entered into a specified one of said external connection terminals; and
said memory access means is adapted for writing data, serially entered from the specified one of said external connection terminals, into said data memory means, and serially outputting the data read from said data memory means to the specified one of said external connection terminals.
10. A printing head capable of being detachably mounted in a printer main body, comprising a head substrate according to claim 9.
11. A printing apparatus comprising:
a printing head according to claim 10;
input means for individually transmitting various signals respectively to a plurality of said external connection terminals of the printing head, thereby causing said recording means to execute a recording operation; and
memory readout means for transmitting various signals to said plural external connection terminals of the printing head, thereby causing said memory access means to execute the data readout.
12. A head substrate according to claim 1, wherein:
said recording means is adapted for recording based on the recording image signal parallel entered into specified ones of said external connection terminals; and
said memory access means is adapted for writing data, parallel entered from the specified plurality of said external connection terminals that parallel receive the recording image signal, into said data memory means, and for serially outputting the data, read from said data memory means, to the specified plurality of said external connection terminals that parallel receive the recording image signal.
13. A printing head capable of being detachably mounted in a printer main body, comprising a head substrate according to claim 12.
14. A printing apparatus comprising:
a printing head according to claim 13;
input means for individually transmitting various signals respectively to a plurality of said external connection terminals of the printing head, thereby causing said recording means to execute a recording operation; and
memory readout means for transmitting various signals to said plural external connection terminals of the printing head, thereby causing said memory access means to execute the data readout.
15. A printing head capable of being detachably mounted in a printer main body, comprising a head substrate according to claim 1.
16. A printing head according to claim 15, wherein said recording means includes a recording element for recording.
17. A printing head according to claim 16, wherein the recording element is a heat generating element.
18. A printing head according to claim 17, wherein the recording is executed by discharging ink by the heat of the heat generating element.
19. A printing apparatus comprising:
a printing head according to claim 15;
input means for individually transmitting various signals respectively to a plurality of said external connection terminals of the printing head, thereby causing said recording means to execute a recording operation; and
memory readout means for transmitting venous signals to said plural external connection terminals of the printing head, thereby causing said memory access means to execute the data readout.
20. A head substrate according to claim 1, wherein the electric power is also used for driving said recording means.
21. A head substrate according to claim 1, wherein connection terminals to which the electric power is applied are different from connection terminals to which electric power driving the recording means is applied.
22. A head substrate according to claim 1, wherein the shutting off of the supply of the electric power is performed by cutting electric power wiring.
23. A printing head capable of being detachably mounted on a printer main body, comprising:
plural external connection terminals for externally entering various signals and electric power;
recording means for recording according to the various signals;
data memory means capable of data readout;
memory access means for reading data stored in said data memory means;
wherein the printing head is adapted so as to be capable of rendering said memroy acess means permanently incapable of data writing into said data memory means by shutting off a supply of the electric power for data writing from said external connection terminals to said memory access means.
24. A printing head according to claim 23, wherein said recording means includes a recording element for recording.
25. A printing head according to claim 24, wherein the recording element is a heat generating element.
26. A printing head according to claim 25, wherein the recording is executed by discharging ink by the heat of the heat generating element.
27. A printing apparatus comprising:
a printing head according to claim 23; and
means for driving the printing head.
28. A printing apparatus according to claim 27, wherein said recording means includes a recording element for recording.
29. A printing apparatus according to claim 28, wherein the recording element is a heat generating element and ink is discharged by the heat generated by the heat generating element.
30. A printing head according to claim 23, wherein the electric power is also used for driving said recording means.
31. A printing head according to claim 23, wherein connection terminals to which the electric power is applied are different from connection terminals to which electric power for driving the recording means is applied.
32. A printing head according to claim 23, wherein the shutting off of the supply of the electric power is performed by cutting electric power wiring.
33. A method for producing a printing head capable of being detachably mounted on a printer main body, comprising:
a step of preparing a head substrate including plural external connection terminals for externally entering various signals and electric power;
a recording step, of recording according to the various signals;
a data memory step, of executing data writing and data readout;
a memory access step, of executing the data writing in said data memory step in response to signals entered via the external connection terminals and electric power and of executing the data readout in response to other signals entered via the external connection terminals; and
permanently disabling the data writing from said data memory step by said memory access step by shutting off a supply of the electric power for data writing from the external connection terminals for use in said memory access step.
34. A method according to claim 33, wherein the shutting off of the supply of the electric power is performed by cutting electric power wiring.
35. A method for producing a printing head capable of being detachably mounted on a printer main body, comprising:
a step of preparing the printing head including plural external connection terminals for externally entering various signals and electric power;
a recording step, of recording according to the various signals;
a data memory step, of executing data writing and data readout;
a memory access step, of executing the data writing in said data memory step in response to signals entered via the external connection terminals and the electric power and of executing the data readout in response to other signals entered via the external connection terminals; and
permanently disabling the data writing into said data memory means in said memory access step by shutting off a supply of the electric power for data writing from the external connection terminals for use in said memory access step.
36. A method for producing the head substrate according to claim 35, wherein:
said writing inhibition step includes cutting off a signal wiring for connecting the external connection terminals, and externally receiving an access permission signal for permitting the data writing, and then is followed by said memory access step.
37. A method for producing the printing head according to claim 35, wherein:
said data memory step includes writing data of plural kinds in succession in said data memory step by performance of said memory access step; and
said writing inhibition step includes individually disabling data overwriting for the data of the plural kinds written in succession in said data memory step by said memory access step.
38. A method according to claim 35, wherein the shutting off of the supply of the electric power is performed by cutting electric power wiring.
39. A head substrate of a printing head capable of being detachably mounted on a printer main body, comprising:
recording means for recording;
data memory means to which data is written and from which data is read; and
memory access means for writing data into said data memory means in response to another signal,
wherein the head substrate is adapted so as to be capable of permanently disabling the data writing into said data memory means by said memory access means by shutting off a supply of the electric power for data writing to said memory access means.
40. A printing head capable of being detachably mounted on a printer main body, comprising:
recording means for recording;
data memory means to which data is written and from which data is read; and
memory access means for writing data into said data memory means in response to electric power and a signal and for reading out data from said data memory means in response to another signal,
wherein the printing head is adapted so as to be capable of permanently disabling the data writing into said data memory means by said memory access means by shutting off a supply of the electric power for data writing to said memory access means.