Patent US4720859A successfully refreshed from Google Patents.
US4720859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and system for the mutual encyphered indentification between data communicating stations and stations for use with such method and system
Assignee: US Philips Corp
•
Filing: 1982-04-05
•
Granted: 1988-01-19
•
Expires: 2002-04-05
Abstract
Abstract A method for transmitting ciphered information between two stations while using session keys. According to the method a mutual identification of the stations (AK, A; A,B) is obtained while using an identification device (ID) comprised in each station. Number values (r 1 , r 2 ), originating from each station, may be exchanged by said identification in a form which is so ciphered that the number values may be recovered by the counterpart only. The session key (t m ) is formed on basis of said number values in a modification device (MODIFI). Ciphered data messages are exchanged between the station using the established session key and a message ciphering/deciphering device (MCRY, MDECRY) comprised in each station. According to the method the mutual identification and the establishment of the session key via an open channel may be obtained by transmitting one separate identification sequence in each direction.
Inventors
- 👤 Tore I. Aaro
- 👤 Torgny O. Rustan
- 👤 Par man
- 👤 Rolf J. Blom
- 👤 Robert Forchheimer
- 👤 Viiveke A. Fak
- 👤 Bror I. Ingemarsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:19
CPC Classifications
G; G07; G07F; G07F7/00; G07F7/08; G07F7/10; G07F7/1008; G06; G06Q; G06Q20/00; G06Q20/30; G06Q20/34; G06Q20/341; G06Q20/36; G06Q20/367; G06Q20/3674; G06Q20/38; G06Q20/388; G06Q20/40; G06Q20/409; G06Q20/4097; G06Q20/40975; G07F7/1016; H; H04; H04L; H04L9/00; H04L9/32; H04L9/3236; H04L9/3271; H04L2209/00; H04L2209/56
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
362 words
A method for transmitting data messages between a first station (A, 32) belonging to a first class of stations and a second station (B, 34) belonging to a second class of stations, said method comprising the steps of: a. generating a first identification sequence (cg1) is said first station to be sent to said second station from a first identification number value (a, r1) and a first ciphering key (kb) by means of a first identification ciphering function (E); b. reproducing said first identification number value in said second station from said first identification sequence by means of a first deciphering key (db) and a second identification ciphering function (D) inverse to said first ciphering function; c. generating a second identification sequence (cg2) in said second station to be sent to said first station from said reproduced first identification number value, from a second identification number value (b, r2) and a second ciphering key (ka) by means of said first identification ciphering function; d. reproducing said second identification number value in said first station from said second identification sequence by means of a second deciphering key (da) and said second identification ciphering function; e. generating a third identification sequence (cg3) in said first station to be sent to said second station from said reproduced second identification number value, by means of a third identification ciphering function (f); f. in an identifying step by means of comparison of a part of a received identification sequence (cg2, cg3) to a locally generated identification number value (r1, r2) after being operated by said third identification ciphering function: identifying in said first station said second station as belonging to said second class, and identifying in said second station said first station as belonging to said first class; g. generating identical message ciphering keys (tm) upon said mutual identification in both said first and second stations based on the respective first and second identification number values for use in a message ciphering function which is different from any identification ciphering function; and h. generating an encyphered message in at least one of said stations by means of said message ciphering key for transmission to the other station.
Claim 2
Independent Claim
362 words
A method for transmitting data messages between a first station (A, 32) belonging to a first class of stations and a second station (B, 34) belonging to a second class of stations, said method comprising the steps of: a. generating a first identification sequence (cg1) is said first station to be sent to said second station from a first identification number value (a, r1) and a first ciphering key (kb) by means of a first identification ciphering function (E); b. reproducing said first identification number value in said second station from said first identification sequence by means of a first deciphering key (db) and a second identification ciphering function (D) inverse to said first ciphering function; c. generating a second identification sequence (cg2) in said second station to be sent to said first station from said reproduced first identification number value, from a second identification number value (b, r2) and a second ciphering key (ka) by means of said first identification ciphering function; d. reproducing said second identification number value in said first station from said second identification sequence by means of a second deciphering key (da) and said second identification ciphering function; e. generating a third identification sequence (cg3) in said first station to be sent to said second station from said reproduced second identification number value, by means of a third identification ciphering function (f); f. in an identifying step by means of comparison of a part of a received identification sequence (cg2, cg3) to a locally generated identification number value (r1, r2) after being operated by said third identification ciphering function: identifying in said first station said second station as belonging to said second class, and identifying in said second station said first station as belonging to said first class; g. generating identical message ciphering keys (tm) upon said mutual identification in both said first and second stations based on the respective first and second identification number values for use in a message ciphering function which is different from any identification ciphering function; and h. generating an encyphered message in at least one of said stations by means of said message ciphering key for transmission to the other station.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1, wherein said first and second identification number values contain first and second random numbers.
Claim 4
Dependent Claim
50 words
A method as claimed in claim 1, wherein said first ciphering key and second ciphering key are public keys and said second deciphering key and first deciphering key are stored in an initializing step with the first ciphering key and second ciphering key, respectively in said first and second stations.
Claim 5
Dependent Claim
54 words
A method as claimed in claim 1, wherein said third identification ciphering function is a one-way function, such that an identification number value may not be recovered even with knowledge of the third identification ciphering function and the identification number value after said number value is operated on by said third identification ciphering function.
Claim 6
Dependent Claim
29 words
A method as claimed in claim 1, wherein each station is provided with break means for breaking a connection under control of a noncorrespondence detected in an identifying step.
Claim 7
Dependent Claim
67 words
A method as claimed in claim 1, wherein: one station is a personal data carrier built as an active card, and at least one station includes means for supplying and evaluating a personal code; and wherein said first step includes initiating the transmission of said identification sequences by an evaluation of a personal code, which evaluation is carried out and accepted internally in one of said stations.
Claim 8
Independent Claim
302 words
A system for transmitting data messages between a first station (A, 32) belonging to a first class of stations and a second station (B, 34) belonging to a second class of stations, comprising: a. means to generate a first identification sequence (cg1) in said first station to be sent to said second station from a first identification number value (b, r1) and a first ciphering key (kb) by means of a first identification ciphering function (E); b. means to reproduce said first identification number value in said second station from said first identification sequence by means of a first deciphering key (db) and a second identification ciphering function (D) inverse to said first ciphering function; c. means to generate a second identification sequency (cg2) in said second station to be sent to said first station from said reproduced first identification number value, from a second identification number value (b, r2) and a second ciphering key (ka) by means of said first identification ciphering function; d. means to reproduce said second identification number value in said first station from said second identification sequence by means of a second deciphering key (da) and said second identification ciphering function; e. means to identify said second station as belonging to said second class in said first station and means to identify said first station as belonging to said first class in said second station; f. means to generate identical message ciphering keys (tm) based on the respective first and second identification number values for use in a message ciphering function which is different from any identification ciphering function upon said mutual identification in both said first and second stations; g. means to generate an enciphered message by means of said message ciphering key for transmission to the other station in at least one of said stations.
Claim 9
Independent Claim
302 words
A system for transmitting data messages between a first station (A, 32) belonging to a first class of stations and a second station (B, 34) belonging to a second class of stations, comprising: a. means to generate a first identification sequence (cg1) in said first station to be sent to said second station from a first identification number value (b, r1) and a first ciphering key (kb) by means of a first identification ciphering function (E); b. means to reproduce said first identification number value in said second station from said first identification sequence by means of a first deciphering key (db) and a second identification ciphering function (D) inverse to said first ciphering function; c. means to generate a second identification sequency (cg2) in said second station to be sent to said first station from said reproduced first identification number value, from a second identification number value (b, r2) and a second ciphering key (ka) by means of said first identification ciphering function; d. means to reproduce said second identification number value in said first station from said second identification sequence by means of a second deciphering key (da) and said second identification ciphering function; e. means to identify said second station as belonging to said second class in said first station and means to identify said first station as belonging to said first class in said second station; f. means to generate identical message ciphering keys (tm) based on the respective first and second identification number values for use in a message ciphering function which is different from any identification ciphering function upon said mutual identification in both said first and second stations; g. means to generate an enciphered message by means of said message ciphering key for transmission to the other station in at least one of said stations.
Claim 10
Dependent Claim
67 words
A system as claimed in claim 7, characterized in that said identification means comprises a number converter for converting said number values while using a transformation function and a comparator for comparing the number value of a first station in the form which is converted internally with the form as converted by a second station and to generate a blocking signal when an agreement fails to appear.
Claim 11
Dependent Claim
38 words
A system as claimed in claim 7 or 8, characterized in that each station furthermore comprises a blocking device for blocking the transmission channel used by said first and second stations whose transmission resulted in said blocking signal.
Claim 12
Dependent Claim
72 words
A system as claimed in claim 7 or 8, in which: at least one station is a personal data carrier built as an active card; at least one station comprises: means for supplying and evaluating a personal code means for activating temporarily said station or said data carrier; and means to initiate the exchange of said number values dependent on an evaluation which is carried out and accepted internally in the station.
Claim 13
Dependent Claim
30 words
A system according to claim 7, characterized in that each station comprises identification means (36), modifying means (38) ciphering and deciphering means (44/46), and message generating and receiving means (40/42).
Claim 14
Dependent Claim
35 words
A system as claimed in claim 11, characterized in that at least one station is provided with key means (32) for entering a personal identification code for comparison (80) with an internally generated code (78).
References Cited (Backward Citations)
US4193131A
Cited
US4206315A
Cited
US4408203A
Cited
US4186871A
Cited
GB2047506A
Cited
US4264782A
Cited
EP0021401A1
Cited
US4471216A
Cited
US4302810A
Cited
US4326098A
Cited
US4393269A
Cited
US4578532A
Cited
US4423287A
Cited
US4652698A
Cited
US4649233A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-18 | 1991-07-20 | 1992-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-18 | 1995-07-20 | 1996-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-18 | 1999-07-20 | 2000-01-19 | $7700.00 | Window Closed / Lapsed |