WO2000013368A1 - Method of authenticating or 'digitally signing' digital data objects - Google Patents

Method of authenticating or 'digitally signing' digital data objects Download PDF

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Publication number
WO2000013368A1
WO2000013368A1 PCT/US1999/018824 US9918824W WO0013368A1 WO 2000013368 A1 WO2000013368 A1 WO 2000013368A1 US 9918824 W US9918824 W US 9918824W WO 0013368 A1 WO0013368 A1 WO 0013368A1
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WO
WIPO (PCT)
Prior art keywords
data object
data
distinct
signature
time
Prior art date
Application number
PCT/US1999/018824
Other languages
French (fr)
Other versions
WO2000013368A8 (en
Inventor
Frederick J. Borgers
Original Assignee
Borgers Frederick J
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
Priority to US14404398A priority Critical
Priority to US09/144,043 priority
Application filed by Borgers Frederick J filed Critical Borgers Frederick J
Publication of WO2000013368A1 publication Critical patent/WO2000013368A1/en
Publication of WO2000013368A8 publication Critical patent/WO2000013368A8/en

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00Cryptographic mechanisms or cryptographic arrangements for secret or secure communication
    • H04L9/32Cryptographic mechanisms or cryptographic arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
    • H04L9/3236Cryptographic mechanisms or cryptographic arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials using cryptographic hash functions
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00Cryptographic mechanisms or cryptographic arrangements for secret or secure communication
    • H04L9/32Cryptographic mechanisms or cryptographic arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
    • H04L9/3247Cryptographic mechanisms or cryptographic arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials involving digital signatures
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00Cryptographic mechanisms or cryptographic arrangements for secret or secure communication
    • H04L9/32Cryptographic mechanisms or cryptographic arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials
    • H04L9/3297Cryptographic mechanisms or cryptographic arrangements for secret or secure communication including means for verifying the identity or authority of a user of the system or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials involving time stamps, e.g. generation of time stamps

Abstract

A data object, such as a document, is combined or associated with signature or authentication data, such as a time-stamp or signature. Both the data object and the signature data are encrypted. Finally, a distinct data object is generated (digested or hashed) from the encrypted data object and signature data, the distinct data object has characteristics determined by the data object and the signature data. The data object may be hashed or digested prior to being combined with the signature data.

Description

METHOD OF AUTHENTICATING OR "DIGITALLY SIGNING" DIGITAL

DATA OBJECTS

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to providing authentication of digital data,

such as document or other data files or objects. More particularly, the present invention

relates to methods of securely appending or otherwise incorporating a digital signature

or indicia of authenticity into a data object.

BACKGROUND OF THE INVENTION AND BACKGROUND ART

There have been several prior attempts to digitally "sign," "notarize," or otherwise

authenticate a digital data object such as a text document. Generally speaking, one

drawback to the storage of, for instance, digital document files, is that it can be difficult

to establish whether the version retrieved or transmitted is the identical document

originally stored or created. A "digital signature" or "notary" is a common nomenclature

for an attempt to provide indicia of authenticity of the digital data.

One such method is found in U.S. Patent Number 5,022,080, June 4, 1991, to

Durst et al., which discloses a method of digitally notarizing a document comprising the

steps of hashing the document, transmitting the digest (or result of the hash) to a trusted

third party, where the digest is combined with a time-stamp, and then encrypting the

combination to produce a "digitally notarized" document. All that is required to

authenticate the document is the key to the encryption technique. Thus, simply by

"breaking the code" the authenticity indicia or the underlying data object can be altered or tampered with.

Other solutions complicate this basic scheme to render it more difficult to break

the code successfully. For instance, U.S. Patent Number 5,373,561, December 13, 1994

to Haber et al., periodically re-encrypts the signature data to take advantage of ever-

increasing computational power and advances in encryption, which also render the

authentic document more susceptible to alteration, decryption, or tampering as time

passes. However, if the user neglects to "update" the encryption, the advantage is lost.

A need exists, therefore, for a method of digitally authenticating a data object that

is not susceptible to future tampering, yet is sufficiently simple as to be implemented in

a practical and efficient manner.

DISCLOSURE OF THE INVENTION

It is a general object of the present invention to provide a method of providing a

data object that can ve verified or authenticated reliably, with minimal risk of tampering.

This and other objects of the present invention are achieved by associating or

combining a data object, such as a document file, with signature or authentication data,

such as a time-stamp or signature. Both the data object and the signature data are

encrypted. Finally, a distinct data object is generated or digested from the combination

of encrypted data object and signature data, the distinct data object has characteristics

determined by the data object and the signature data.

According to the preferred embodiment of the present invention, the generation

of the distinct data object is achieved using a hashing algorithm, such as SHA-1.

According to the preferred embodiment of the present invention, the signature or

authentication data is provided by a trusted third party. The data object transmitted to the

third party may be a digest or hash of the data object to preserve the confidentiality of the

data object.

According to the preferred embodiment of the present invention, the encryption

step is achieved by a symmetric encryption algorithm.

According to the preferred embodiment of the present invention, the authenticity

of the original data object is confirmed by reproducing the distinct data object by

identically encrypting a data object identical to the original, generating another distinct

data object, and comparing the second and first distinct data objects for identity. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a high-level flow chart depicting the steps of the method according to

the preferred embodiment of the present invention, and more particularly the steps of

proving a data object with authentication or signature data.

Figure 2 is a block diagram schematically depicting a portion of the method of

Figure 1 according to the preferred embodiment of the present invention.

Figure 3 is a high-level flow chart illustrating the steps of the method according

to the preferred embodiment of the present invention, and more particularly of the steps

of authenticating a data object provided with authentication data.

Figure 4 is a block diagram schematically depicting a portion of the method of

Figure 3 according to the preferred embodiment of the present invention.

MODE(S) FOR CARRYING OUT THE INVENTION

Referring now to the Figures, and specifically to Figure 1, a high-level flow-chart

depicts the basic steps of a portion of the method according to the present invention.

First, at block 11, a first data object or item is provided by a user or customer of the

method. The data object or item could be a document, drawing, image file, or any item

or segment of data that the user desires to provide with the ability to be authenticated or

verified in the future.

At block 13, the data object is combined or associated with signature or

authentication data. The signature or authentication may include the time of creation of

the data object, the name of the author of the object, predetermined characters indicating

the origin of the object, or virtually any other data the user desires to serve as evidence

of authenticity of the underlying data object. According to the preferred embodiment of

the present invention, the authentication data is a "time stamp" that comprises, for

instance, the time and date from the "Atomic Clock" maintained by the United States

Naval Observatory (e.g., 22: 13.02; 4 April 1998). The signature or authentication data

is appended, concatenated, or otherwise conventionally combined or associated with the

data object. As discussed in greater detail with reference to Figure 2, the time stamp or

other signature or authentication data is provided by a trusted third party, perhaps the

vendor of the method, who also keeps meticulous records of the method used to combine

or associate the data object with signature or authentication data.

Next, at block 15, the combination of the data object and signature or

authentication data is encrypted using conventional symmetric secret-key, asymmetric public-key techniques or other combining techniques which use a key known only to the

trusted third party. The encryption technique could be as simple as appending or

concatenating a selected, random text or character string to the data object. For maximum

security, it is preferable that the trusted third-party employ secret-key techniques and

maintain a record of the encryption technique along with any secret-keys, for future use

in authentication of the data object. The preferred encryption method or algorithm is

RC5.

Finally, at block 17, the encrypted data object is digested or hashed using a hash

routine to generate a distinct data object. A hash routine generates a data string that is

characteristic of the underlying data object that is subjected to the hash routine. The

preferred hashing algorithm is SHA-1. There are several hashing routines or algorithms,

such as SHA-1, that are suitable for use in the method according to the present invention.

All of these hashing routines or algorithms share the following characteristics:

• the underlying data object cannot be reproduced from the hashed data

string (it is a one-way or irreversible process);

• the routine produces a data string of fixed length; and

• the routine will not yield the same data string for two different data objects.

Hashing is sometimes referred to as a method of encryption, but this is inaccurate: the

very essence of encryption is that it can be decrypted or the process reversed. Hashing,

by its very nature, is not reversible. According to the preferred embodiment of the

present invention, the hashing or digesting step may comprise application of a single

hashing algorithm or routine to the encrypted data object and signature data. Alternatively, the hashing step may comprise multiple applications of the same or

different hashing algorithms.

The result of the hashing step is a distinct data object that has characteristics of

both the underlying data object and the signature or authentication data. The distinct data

object may be appended to or separate from the underlying data object. The distinct data

object and the signature or authentication data is transmitted, along with the original data

object to a recipient party to permit the recipient party to later confirm the authenticity

of the original data object and/or the combination of the data object and the signature or

authentication data.

Figure 2 is a block diagram depicting elements and relationships between entities

performing the steps of the method according to the present invention. According to the

preferred embodiment of the present invention, the encryption and hashing steps are

performed on the user's computer 19 which may be a personal computer, a client/server

workstation, terminal for a mainframe or minicomputer or the like. The signature or

authentication data is provided by a trusted third party 21, who also provides the

encryption and hashing algorithms and keeps a record of the encryption or combining

techniques and any secret keys for use in future authentication. Alternatively, the

encryption and hashing algorithms are resident on and maintained by user's system 19.

According to one embodiment of the invention, the original data object is hashed

and then sent to the trusted third party 21 to preserve the confidentiality of the original

data object. In this embodiment, the trusted third party performs the encryption and

hashing or digesting steps and returns the resulting distinct data object and authentication data to user 19 to associate with or combine with the original data object.

Communication between user 19 and trusted third party 21 is accomplished in a

number of ways: through modem line, Tl line, frame relay link, or cable modem, or http

protocol (each with appropriate security). Trusted third party 21 maintains records of any

encryption keys, the encryption technique and hashing algorithm(s) for future use by the

party that later performs authentication of the document.

Figure 3 is a high-level flow chart depicting the steps of the authentication portion

of the method according to the present invention. To authenticate the data object, an

original copy, block 31, of the data object, identical to the first, is combined with

signature or authentication data, at block 33. The original copy of the data object and

signature or authentication data can be provided by the originator, or can be kept by the

trusted third party along with the encryption and/or hashing algorithms. After the copy

of the original data object is combined with the authentication or signature data, the

combinations is encrypted in an identical fashion to the original, at block 35. At block

37, the resulting encrypted data object is then hashed or digested identically to the first,

and the resulting distinct data object compared with the original data object (the result of

block 17 in Figure 1) and the two are compared for identity. If the two are identical, the

underlying data object (or the copy) is thus verified or authenticated. If not identical, the

data object or copy is not authenticated and cannot be trusted (i.e., the copy or document

purporting to be original has been altered and is not identical to the first or the

authentication data has been altered).

Figure 4 is a block diagram depicting elements and relationships between entities perforating the steps of the authentication portion of the method according to the present

invention. According to the preferred embodiment of the present invention, the

authentication steps are performed by a trusted party, perhaps the vendor of the method

as the recipient party 25 using information provided by the trusted third party, the

originator or user, or a combination of the two. The distinct data objects are input to a

comparator or a computer algorithm operable to compare data for identity. The output

of the comparator verifies the authenticity (or lack thereof).

According to the preferred embodiment of the present invention, the method is

performed using software resident on the document or data object originator's computer.

The encryption and digesting occurs on the trusted third party's computer with the input

and results being communicated to and from the trusted third party as described above.

The recipient of the "authenticated" data object can request verification through the

trusted third party, depending upon which of the parties maintains the requisite

encryption technique, hashing algorithm, combination method, and any encryption keys.

The method according to the present invention provides an improved method of

digitally signing or otherwise authenticating digital data objects. Because the hashing or

digesting step is one-way or irreversible, the encrypted portion of the "signature" is not

susceptible to unauthorized decryption, even by marked advances in computational

power. Because of this advantage, the trusted third party or vendor must keep scrupulous

records of the encryption or combining techniques, hashing methods and encryption keys

employed in providing the signature or authentication data.

The invention has been described with reference to preferred embodiments thereof. It is thus not limited, but is susceptible to variation and modification without departing

from the scope and spirit of the invention, which is defined by the claims, which follow.

Claims

1. A method of securely associating signature data with other data, the method comprising the steps of: associating a data object with signature data; encrypting both the data object and the signature data; and generating a distinct data object from the encrypted data object and signature data, the distinct data object having characteristics determined by the data object and the signature data.
2. The method according to claim 1 further comprising the step of: delivering the distinct data object and signature data to a recipient party.
3. The method according to claim 2, further comprising the step of: validating the distinct data object and signature data combination by: associating a second data object, identical to the first, with the signature data; encrypting the second data object and the signature data using an encryption method identical to that employed in encrypting the first data object and the signature data; generating a second distinct data object from the encrypted second data object and the signature data using an method identical to that employed in generating the distinct data object; and comparing the distinct and second distinct data objects for identity.
4. The method according to claim 1, wherein the signature data is provided by a trusted party.
5. The method according to claim 1, wherein the encrypting step is performed using a symmetric data encryption technique.
6. The method according to claim 1, wherein the step of generating the distinct data object is performed using a hash routine.
7. A method of providing a time-stamp for a data object comprising the steps of: generating a distinct value for the data object; associating signature data with the distinct value to produce a signed data object; encrypting the signed data object; and generating a second distinct value from the encrypted signed data object, the second distinct data object having characteristics of the encrypted signed data object.
8. The method according to claim 7 further comprising the step of: delivering the second distinct data object and signature data to a recipient party.
9. The method according to claim 8, further comprising the step of: validating the second distinct data object and signature data combination by: generating a third distinct value, identical to the distinct value; associating a second signature data, identical to the first, with the third distinct value to produce a second signed data object; and encrypting the second signed data object using an encryption method identical to that employed in encrypting the first signed data object; generating a fourth distinct value from the encrypted second signed data object using method identical to that employed in generating the second distinct value; and comparing the fourth distinct value and second distinct value for identity.
10. The method according to claim 7, wherein the signature data is provided by a trusted party.
11 The method according to claim 7, wherein the encrypting step is performed using a symmetric data encryption technique.
12. The method according to claim 7, wherein the step of generating the distinct value is performed using a hash routine.
13. A method of providing a time-stamp for a data object comprising the steps of: generating a distinct value for the data object by performing a hash routine on the data object; associating a time-stamp with the distinct value to produce a time-stamped data object; encrypting the time-stamped data object; and generating a second distinct value from the encrypted time-stamped data object by performing a hash routine on the encrypted time-stamped data object.
14. The method according to claim 13 further comprising the step of: delivering the second distinct data object and time-stamp to a recipient party.
15. The method according to claim 13, further comprising the step of: validating the second distinct data object and time-stamp combination by: generating a third distinct value, identical to the distinct value; associating a identical time-stamp with the third distinct value to produce a second time-stamped data object encrypting the second time-stamped data object using the identical encryption method; generating a forth distinct value from the encrypted second time-stamped data object; and comparing the fourth distinct value and second distinct value for identity.
16. The method according to claim 13, wherein the time stamp is provided by a trusted party.
17. The method according to claim 13, wherein the encrypting step is performed using a symmetric data encryption technique.
PCT/US1999/018824 1998-08-31 1999-08-27 Method of authenticating or 'digitally signing' digital data objects WO2000013368A1 (en)

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US14404398A true 1998-08-31 1998-08-31
US09/144,043 1998-08-31

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ES2165812A1 (en) * 2000-07-13 2002-03-16 Fab Nac Moneda Y Timbre Es Independent device for electronic certification of time
EP1217784A1 (en) * 2000-12-22 2002-06-26 timeproof Time Signature GmbH Method and apparatus for generating a digital signature
GB2405227A (en) * 2003-08-16 2005-02-23 Ibm Authenticating publication date of a document
US6978929B2 (en) 2000-06-19 2005-12-27 The United States Postal Service Systems and methods for providing mail item retrieval
US7295997B2 (en) 2000-06-19 2007-11-13 United States Of America Postal Service Method for shipping a package privately to a customer
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US8388709B2 (en) 2007-12-06 2013-03-05 Ceratizit Austria Gesellschaft GmbH Coated article
US8661862B2 (en) 2004-06-29 2014-03-04 The United States Postal Service Cluster box mail delivery unit having security features
RU2653316C1 (en) * 2017-02-20 2018-05-07 Вадим Викторович Алашеев Method of authentication of radio network correspondents
USD821679S1 (en) 2005-06-29 2018-06-26 United States Postal Service Cluster box mail delivery unit

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Cited By (28)

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Publication number Priority date Publication date Assignee Title
WO2001024437A3 (en) * 1999-09-30 2001-09-07 Us Postal Service Systems and methods for authenticating an electronic message
US7484088B2 (en) 2000-03-17 2009-01-27 United States Postal Service Methods and systems for proofing identities using a certificate authority
US8429234B2 (en) 2000-03-17 2013-04-23 United States Postal Service Methods and systems for providing an electronic account to a customer
US7984289B2 (en) 2000-03-17 2011-07-19 United States Postal Service Methods and systems for establishing an electronic account for a customer
US7802093B2 (en) 2000-03-17 2010-09-21 United States Postal Service Methods and systems for proofing identities using a certificate authority
US7711950B2 (en) 2000-03-17 2010-05-04 United States Postal Services Methods and systems for establishing an electronic account for a customer
US8356187B2 (en) 2000-03-17 2013-01-15 United States Postal Service Methods and systems for providing a secure electronic mailbox
US8352551B2 (en) 2000-03-17 2013-01-08 United States Postal Service Methods and systems for providing an electronic account to a customer
US7376598B2 (en) 2000-06-19 2008-05-20 United States Postal Service Method, system, and computer readable medium for shipping a package to a customer while preserving customer privacy
US7295997B2 (en) 2000-06-19 2007-11-13 United States Of America Postal Service Method for shipping a package privately to a customer
US6978929B2 (en) 2000-06-19 2005-12-27 The United States Postal Service Systems and methods for providing mail item retrieval
US7848961B2 (en) 2000-06-19 2010-12-07 The United States Postal Service System, method and article of manufacture for shipping a package privately to a customer
US8244809B2 (en) 2000-06-20 2012-08-14 United States Postal Service System and methods for electronic message content identification
ES2165812A1 (en) * 2000-07-13 2002-03-16 Fab Nac Moneda Y Timbre Es Independent device for electronic certification of time
US7729957B2 (en) 2000-07-25 2010-06-01 United States Postal Service Item attribute preverification
EP1217784A1 (en) * 2000-12-22 2002-06-26 timeproof Time Signature GmbH Method and apparatus for generating a digital signature
US7337944B2 (en) 2001-02-20 2008-03-04 United States Postal Service Universal delivery and collection box unit (UDCBU)
US8166115B2 (en) 2001-06-20 2012-04-24 United States Postal Service Systems and methods for electronic message content identification
US8572049B2 (en) 2003-08-16 2013-10-29 International Business Machines Corporation Document authentication
GB2405227A (en) * 2003-08-16 2005-02-23 Ibm Authenticating publication date of a document
US8661862B2 (en) 2004-06-29 2014-03-04 The United States Postal Service Cluster box mail delivery unit having security features
USD821679S1 (en) 2005-06-29 2018-06-26 United States Postal Service Cluster box mail delivery unit
EP2472430A1 (en) 2006-12-01 2012-07-04 David Irvine Self encryption
WO2008065341A2 (en) 2006-12-01 2008-06-05 David Irvine Distributed network system
US8388709B2 (en) 2007-12-06 2013-03-05 Ceratizit Austria Gesellschaft GmbH Coated article
WO2009074436A1 (en) * 2007-12-10 2009-06-18 Siemens Aktiengesellschaft Method and device for detecting whether a vehicle has exceeded a speed limit
US20100302362A1 (en) * 2007-12-10 2010-12-02 Siemens Aktiengesellschaft Method and device for detecting whether a vehicle has exceeded a speed limit
RU2653316C1 (en) * 2017-02-20 2018-05-07 Вадим Викторович Алашеев Method of authentication of radio network correspondents

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