Information Technology Reference
In-Depth Information
efforts. On the one hand, the holder of a pseudonym can prove that he gener-
ated the pseudonym without disclosing it. On the other hand, the verifier of a
disclosed pseudonym can be sure, that the presenter of the pseudonym is the
original holder (i.e. the person who generated it).
However, there are still some open problems and possible extensions. These
questions, which are scope of ongoing research include:
Enforcement of Disclosure:
One of the major drawbacks of our approach is,
that the disclosure of the pseudonym is completely under control of the holder.
In specific application scenarios, this is an appreciated feature. In other scenarios
we would like some mechanism which ensures, that a pseudonym can be disclosed
under certain (previously specified) circumstances. Escrowing of the private key
(
d, n
) is a straight-forward solution for this problem; but there may be better
ones.
Certification of the Private Exponent
d
:
A user may certify his private ex-
ponent
d
(note NOT his public key which would include
n
) at a certification
authority. So he can later on prove that a specific pseudonym belongs to his
identity.
Other Types of Pseudonyms:
Different mechanisms and different types of
common components influence the properties (pre-computations, generation ef-
forts, length of pseudonym, proof of ownership, disclosure and security) of the
generated pseudonym.
Pseudonyms by means of Unique Primes:
Here, we will combine the orig-
inal scheme of generating unique primes and the proposed scheme for unique
pseudonyms in order to overcome the drawback discussed in section 3.
Proof of Binding between ID and Pseudonym:
By now, the only way to
prove the binding between the ID of a user presenting a certain pseudonym, is
to disclose the pseudonym.
References
1. Chaum, D.: Untraceable electronic mail, return addresses, and digital pseudonyms.
Commun. ACM
, 24(2) (1981) 84-88
2. Heikkila, J., Holmstrm, U.: Secure digital pseudonyms for privacy and liability,
Master Thesis, Pennsylvania State University, November 15 (2002)
3. Horster, P.: Dublettenfreie Schlusselgenerierung durch isolierte Instanzen.
Chip-
karten, DuD-Fachbeitrage, Vieweg Verlag
(1998)
4. Horster,
P.,
Schartner,
P.:
Bemerkungen
zur
Erzeugung
dublettenfreier
Primzahlen.
Proceedings of Sicherheitsinfrastrukturen
(1998)
5. Horster, P., Schartner, P., Wohlmacher, P.: Key Management.
Proceedings of the
IFIP TC11 14th international Information Security
(1998) 37-48
6. Horster, P., Schartner, P., Wohlmacher, P.: Special Aspects of Key Generation.
Information Technology: Science-Technique-Technology-Education-Health, Printed
Scientific Works, Kharkov
(1998) 345-350
