NO895116D0 - PROCEDURE FOR REVERSING AN ENTRY ON A NON-CODED KEYBOARD AND CIRCUIT FOR IMPLEMENTATION OF THE PROCEDURE. - Google Patents

PROCEDURE FOR REVERSING AN ENTRY ON A NON-CODED KEYBOARD AND CIRCUIT FOR IMPLEMENTATION OF THE PROCEDURE.

Info

Publication number
NO895116D0
NO895116D0 NO895116A NO895116A NO895116D0 NO 895116 D0 NO895116 D0 NO 895116D0 NO 895116 A NO895116 A NO 895116A NO 895116 A NO895116 A NO 895116A NO 895116 D0 NO895116 D0 NO 895116D0
Authority
NO
Norway
Prior art keywords
procedure
circuit
keyboard
outputs
reversing
Prior art date
Application number
NO895116A
Other languages
Norwegian (no)
Other versions
NO177073B (en
NO895116L (en
NO177073C (en
Inventor
Philippe Verrier
Roger Poulenard
Hartmut Fink
Original Assignee
Bull Sa
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bull Sa filed Critical Bull Sa
Publication of NO895116D0 publication Critical patent/NO895116D0/en
Publication of NO895116L publication Critical patent/NO895116L/en
Publication of NO177073B publication Critical patent/NO177073B/en
Publication of NO177073C publication Critical patent/NO177073C/en

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

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Human Computer Interaction (AREA)
  • Computer Security & Cryptography (AREA)
  • Software Systems (AREA)
  • Input From Keyboards Or The Like (AREA)
  • Communication Control (AREA)
  • Storage Device Security (AREA)

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>
NO895116A 1988-12-20 1989-12-19 Method for identifying activated key in a non-encoded keyboard array, as well as circuit for implementing the method NO177073C (en)

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 (4)

Publication Number Publication Date
NO895116D0 true NO895116D0 (en) 1989-12-19
NO895116L NO895116L (en) 1990-06-21
NO177073B NO177073B (en) 1995-04-03
NO177073C NO177073C (en) 1995-07-12

Family

ID=9373142

Family Applications (1)

Application Number Title Priority Date Filing Date
NO895116A NO177073C (en) 1988-12-20 1989-12-19 Method for identifying activated key in a non-encoded keyboard array, as well as circuit for implementing the 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)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
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

Also Published As

Publication number Publication date
NO177073B (en) 1995-04-03
NO895116L (en) 1990-06-21
FR2641656A1 (en) 1990-07-13
ATE97245T1 (en) 1993-11-15
NO177073C (en) 1995-07-12
DE68910657D1 (en) 1993-12-16
FR2641656B1 (en) 1991-08-02
ES2048311T3 (en) 1994-03-16
HK80697A (en) 1997-06-20
EP0375546A1 (en) 1990-06-27
EP0375546B1 (en) 1993-11-10
DE68910657T2 (en) 1994-02-24

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Legal Events

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