HK80697A - Method for distorting the key identification of an uncoded keyboard and circuit for carrying out this method - Google Patents
Method for distorting the key identification of an uncoded keyboard and circuit for carrying out this methodInfo
- Publication number
- HK80697A HK80697A HK80697A HK80697A HK80697A HK 80697 A HK80697 A HK 80697A HK 80697 A HK80697 A HK 80697A HK 80697 A HK80697 A HK 80697A HK 80697 A HK80697 A HK 80697A
- Authority
- HK
- Hong Kong
- Prior art keywords
- keyboard
- distorting
- circuit
- carrying
- outputs
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M11/00—Coding in connection with keyboards or like devices, i.e. coding of the position of operated keys
- H03M11/20—Dynamic coding, i.e. by key scanning
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
- G06F21/70—Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer
- G06F21/82—Protecting input, output or interconnection devices
- G06F21/83—Protecting input, output or interconnection devices input devices, e.g. keyboards, mice or controllers thereof
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/02—Input arrangements using manually operated switches, e.g. using keyboards or dials
- G06F3/023—Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
Abstract
The present invention relates to a method for distorting and the circuit for carrying out this method. The method of distorting consists: a) in output-connecting all the rows and columns of the keyboard to the outputs of a first register (160) of a parallel input-output interface (16) by way of a circuit (163, 166, 164); b) in connecting all the rows and columns of the keyboard to the inputs of the second register (167) of the input-output interface; c) in randomly drawing the order in which the outputs are to be scanned; d) in setting at least one of the outputs to "1" and in observing whether one of the corresponding inputs is at "1"; e) in the contrary case, in scanning each of the remaining lines one by one while setting it to "1" until the associated input is at the value "1"; f) in repeating steps d) and e) to determine the column or respectively the line corresponding to the depressed key of the keyboard. <IMAGE>
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR8816786A FR2641656B1 (en) | 1988-12-20 | 1988-12-20 | METHOD FOR INTERFERING THE IDENTIFICATION OF A KEY FROM AN UNCODED KEYBOARD, AND CIRCUIT FOR IMPLEMENTING THE METHOD |
Publications (1)
Publication Number | Publication Date |
---|---|
HK80697A true HK80697A (en) | 1997-06-20 |
Family
ID=9373142
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
HK80697A HK80697A (en) | 1988-12-20 | 1997-06-12 | Method for distorting the key identification of an uncoded keyboard and circuit for carrying out this method |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0375546B1 (en) |
AT (1) | ATE97245T1 (en) |
DE (1) | DE68910657T2 (en) |
ES (1) | ES2048311T3 (en) |
FR (1) | FR2641656B1 (en) |
HK (1) | HK80697A (en) |
NO (1) | NO177073C (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR930005841B1 (en) * | 1990-10-27 | 1993-06-25 | 삼성전자 주식회사 | Circuit and method for key scanning |
FR2692378B1 (en) * | 1992-06-12 | 1994-07-29 | Dassault Automatismes Telecomm | IMPROVED SECURITY KEYBOARD UNIT. |
GB9224524D0 (en) * | 1992-11-24 | 1993-01-13 | Vecta Ltd | A security system and a method |
US5832206A (en) * | 1996-03-25 | 1998-11-03 | Schlumberger Technologies, Inc. | Apparatus and method to provide security for a keypad processor of a transaction terminal |
GB2333883B (en) * | 1998-01-28 | 2002-10-16 | Markus Guenther Kuhn | Low cost countermeasure against compromising electromagnetic computer emanations |
CN105353889B (en) * | 2015-11-29 | 2018-07-06 | 恒宝股份有限公司 | A kind of random scanning keyboard and its scan method |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1984004614A1 (en) * | 1983-05-13 | 1984-11-22 | Ira Dennis Gale | Data security device |
NL8401989A (en) * | 1984-06-22 | 1986-01-16 | Nederlanden Staat | VIDEO ENTRY STATION WITH IMAGE LINE SCRAPE. |
SE448803B (en) * | 1986-05-22 | 1987-03-16 | Ljungmans Ind Ab | WAY TO PREVENT UNAUTHORIZED ACCESS OF INFORMATION |
-
1988
- 1988-12-20 FR FR8816786A patent/FR2641656B1/en not_active Expired - Fee Related
-
1989
- 1989-12-19 NO NO895116A patent/NO177073C/en not_active IP Right Cessation
- 1989-12-20 AT AT89403570T patent/ATE97245T1/en not_active IP Right Cessation
- 1989-12-20 ES ES89403570T patent/ES2048311T3/en not_active Expired - Lifetime
- 1989-12-20 DE DE89403570T patent/DE68910657T2/en not_active Expired - Lifetime
- 1989-12-20 EP EP89403570A patent/EP0375546B1/en not_active Expired - Lifetime
-
1997
- 1997-06-12 HK HK80697A patent/HK80697A/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
EP0375546B1 (en) | 1993-11-10 |
FR2641656B1 (en) | 1991-08-02 |
NO177073B (en) | 1995-04-03 |
FR2641656A1 (en) | 1990-07-13 |
NO895116D0 (en) | 1989-12-19 |
DE68910657T2 (en) | 1994-02-24 |
DE68910657D1 (en) | 1993-12-16 |
ATE97245T1 (en) | 1993-11-15 |
ES2048311T3 (en) | 1994-03-16 |
NO895116L (en) | 1990-06-21 |
NO177073C (en) | 1995-07-12 |
EP0375546A1 (en) | 1990-06-27 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Change of ownership |
Owner name: CP8 TRANSAC Free format text: FORMER OWNER(S): BULL S.A |
|
AS | Change of ownership |
Owner name: CP8 TECHNOLOGIES Free format text: FORMER OWNER(S): BULL CP8 |
|
CHPA | Change of a particular in the register (except of change of ownership) | ||
PF | Patent in force | ||
PE | Patent expired |
Effective date: 20091219 |