Comments on the
TS 102176 Part 1 v. 0.2.0
Georg Illies
Bundesamt für Sicherheit in der Informationstechnik
Georg Illies / 25th November 2004
Comments and Suggestions for
the Annex

Annex C: Most of its content can be found already in the
main part and in ISO/IEC 18032, so Annex C
should be reduced to section C.2

Annex D: Cite a paper on ECC parameters produced by
the ECC Brainpool (to become an RFC):
class number condition + standard curves

Annex G: Silverman´s method (predictions from any kinds
of different challenges and algos) is dubious.
Section G.3.2 is too „optimistic“.
Georg Illies
25.11.2004
Slide 2
Recommendations for Chapter 10
 No predictions for more than 10 years.
 Regard Lenstra/Verheul´s „computationally equivalent security“
analysis as „liberal view“ recommendations (alias „lower lower
limit“) for the next 5-6 years.
This is consistent with definitions 10.1 and 10.2 of the TS
and section 1.3 of the L/V paper.
 After 6 years even L/V is maybe not enough as „unexpected
progress“ becomes more probable.
 Try to get an almost equal security level for all components.
Georg Illies
25.11.2004
Slide 3
Recommendations for Chapter 10
(„lower lower limit“)
 RSA:
1024 for 3 years
>1250 for 5 years
2048 for 8 years
? for 10 years
 ECC: order q of base point: 160 bit for 2 years
180 bit for 5 years
224 bit for 8 years
 DSA: similar as RSA and ECC but bit-lengths and hash
functions should be compatible with FIPS 186-3.
 level: about 80 bits for 5-6 years, about 100 bit after that
Georg Illies
25.11.2004
Slide 4
Questions about Chapters 7, 11 and 12
 Which signature suites should be added, which
OIDs should be added?
 Shouldn´t MD5 be banned from the TS?
 What is the reason for prefering DSA rather than RSA
in 12.2.2 and 12.2.5?
 Wouldn´t it make sense to add items „May support
EC(G)DSA“ to all the tables in 12.2?
Georg Illies
25.11.2004
Slide 5
Contact
Bundesamt für Sicherheit in der
Informationstechnik (BSI)
Dr. Georg Illies
Postfach 20 03 63
D-53133 Bonn
Germany
Tel: +49 (0)1888-9582-658
Fax: +49 (0)1888-9582-90658
georg.illies@bsi.bund.de
www.bsi.bund.de
www.bsi-fuer-buerger.de
Georg Illies
25.11.2004
Slide 6