Abstract

In paper-based workflow systems, signatures of individuals or groups of people have been used extensively for different purposes. Currently there are numerous studies on computerizing workflow systems. Also there are studies on implementing digital signatures in electronic media. But the diversified purposes of a signature in workflow makes a straightforward implementation of digital signature schemes inadequate. There are few studies on the implication of different signature purposes on electronic workflow systems. The purposes of signature are closely associated with the two modes of decision making, namely single and group. These two modes of decision making in turn lead to single and group signatures. This paper reports our comprehensive studies on signature purposes. These include the analysis of common signature purposes in workflow, classification of these purposes, classification of modes of decision making associated with these signature purposes, signing and validation requirements for handling these signature purposes, and finally an architecture to be incorporated in workflow engines for handling these signature purposes. In summary, this paper addresses a commonly neglected problem in information systems research: management control by signature in workflow.

Author Keywords: Secure workflow; Signature purposes

Article Outline

1. Introduction

2. Background

2.1. Liaison workflow model and Liaison workflow engine architecture

2.2. Digital signature

3. A taxonomy of signature purposes

3.1. Authentication

3.2. Integrity

3.3. Confidentiality

3.4. Authorization

3.5. Accountability

4. Modes of decision making

4.1. Single mode

4.2. Group decision making mode

4.2.1. Sequential multiple signature

4.2.2. Parallel multiple signature

4.2.2.1. Fork

4.2.2.2. Join

4.3. Anonymous-group mode

5. Relations between signature purposes and modes of decision making

6. Signature fields

6.1. Signature as fields

6.2. Signature on selected fields

6.3. Multiple signatures

7. Signature manager

7.1. Public key management

7.2. Protocol of signing with SM

7.3. Protocol of validating with SM

8. Realizing different signature purposes

8.1. Authentication

8.2. Integrity

8.3. Confidentiality

8.4. Authorization

8.5. Accountability

8.5.1. Originality

8.5.2. Responsibility

8.5.3. Time stamping

8.5.4. Being informed

8.5.5. Witness and non-repudiation

9. Procedures for handling of group decision makings

9.1. Sequential multiple signatures

9.2. Parallel multiple signature

9.3. Anonymous

10. Conclusion

Acknowledgements

References

Vitae