Method for generating a digital signature

Patent metadata

Field	Value
Publication number	US-10841099-B2
Application number	US-201515327804-A
Country	US
Kind code	B2
Filing date	Jul 17, 2015
Priority date	Jul 31, 2014
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

Method for generating a digital signature for a digital content using a computer and trustworthy signature hardware connected thereto for data exchange, includes generating a message digest from the digital content by an application executed on the computer; generating descriptive data relating to the electronic digital signature; transmitting the message digest and the descriptive data to the trustworthy signature hardware; outputting the descriptive data at an output device of the trustworthy signature hardware; carrying out a user interaction as precondition for the continuation of the method; generating signature data from the message digest and the descriptive data by the trustworthy signature hardware; and transmitting the signature data from the trustworthy signature hardware to the computer and in particular the application.

First claim

The invention claimed is:

1. A method performed by signature hardware for generating a digital signature, the method comprising:
receiving a message digest and descriptive data from an application executed on a computer, the message digest being generated from digital content, the descriptive data relating to a desired digital signature;
outputting the received descriptive data in a representation perceptible to humans;
receiving validation data from an external source in response to the outputting;
generating signature data from the message digest and the descriptive data based on a linking of the message digest with the descriptive data in response to the receiving the validation data, the signature data corresponding to the desired digital signature; and
transmitting the signature data to the application, wherein the message digest is generated by executing a one-way function on the digital content, wherein the method further comprises executing the one-way function on the descriptive data for generating a hash value having a length of the message digest, and wherein the linking further comprises executing an exclusive-or operation between the message digest and the generated hash value.

2. The method according to claim 1 , wherein the generating the signature data generates at least part of the signature data based on both the message digest and the descriptive data.

3. The method according to claim 2 , wherein the linking includes executing a one-way function on at least one of the descriptive data or the message digest.

4. The method according to claim 3 , wherein the message digest is generated by executing the one-way function.

5. The method according to claim 1 , wherein the receiving the validation data includes receiving the validation data via an input interface of the signature hardware.

6. The method according to claim 5 , wherein the validation data includes user authentication data.

7. The method according to claim 6 , wherein the user authentication data includes a password or a biometric feature.

8. The method according to claim 1 , wherein the descriptive data depends on the digital content.

9. The method according to claim 8 , wherein the descriptive data is extracted from the digital content at a determined or marked region of the digital content.

10. The method according to claim 8 , wherein the descriptive data is derived from a text input of a user, a screen view selected by the user or a speech playback of the digital content selected by the user.

11. The method according to claim 10 , wherein the outputting the descriptive data includes displaying the text or screen view on a display of the signature hardware, or reproducing the text or speech playback by a loudspeaker of the signature hardware.

12. The method according to claim 11 , wherein the reproducing the text includes generating a synthetic speech reproduction of the text.

13. The method according to claim 1 , wherein the signature data is transmitted to the application to be combined with the descriptive data and the digital content to form a signed digital content.

14. The method according to claim 1 , wherein a correspondence of the signature data to the message digest and the descriptive data is checked to verify that the signature data is valid.

15. Signature hardware, comprising:
a memory having computer-readable instructions stored thereon; and
at least one processor communicatively coupled to the memory and configured to execute the computer-readable instructions to carry out the method according to claim 1 .

16. A non-transitory computer-readable medium storing digitally coded instructions that, when executed by at least one processor, cause the at least one processor to perform the method according to claim 1 .

Assignees

• Bundesdruckerei Gmbh

Inventors

• Morgner Frank

Classifications

• H04L9/3226

  using a predetermined code, e.g. password, passphrase or PIN (network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083) · CPC title

• H04L2209/88

  Medical equipments · CPC title

• H04L9/3234

  involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token (network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853) · CPC title

• H04L9/3247 Primary

  involving digital signatures · CPC title

• G06Q20/3827

  Use of message hashing · CPC title