1

eID validations servicesHoucine Bel Mamoune

Unit manager

eID Technical Drill down Session

7 April 2005

22

eID validations services

Introduction

eID CA profile and hierarchy

eID Repository

eID LDAP

eID CRL/delta CRL

eID OCSP

Q&A

33

Introduction

eID Card Manufacturer

eID Certificate Authority

CitizenBelgian National Register

Belgian municipalities

PUK & PINPUK & PIN

44

Chain of Trust

Belgium Root CABelgium Root CABelgium Root CA off line

CA Tree structure

Relying party trusts the Belgium Root CA key

Belgium Root CA issues Citizen CA certificates

Relying party verifies certificate along a certificate path leading to the root.

Citizen CACitizen CA

Citizen CACitizen CA

Citizen CACitizen CA

Auth. Citizen Auth. Citizen cert.cert.

Sign. Citizen Sign. Citizen cert.cert.

eID CA profile and hierarchy

55

eID CA profile and hierarchy

Certificate Serial Number (unique)

Unique name identifying certificate owner

Certificate usage (Sign./Auth.)

Validity period (5 year)

Public key

Issuer name & signature

Technical informationVersion (3)

Signature algorithm

Authority info access

…

Subject: Serial Number = 12345678901G = John FitzgeraldSN = DoeCN = John Doe (Signature)C = BE

Public key:

Validity: 1/07/2003 10:03:00 1/07/2008 10:03:00

Certificate Serial Number: 3214

Issuer: CA-Name

Signature: CA Digital signature

66

eID CA profile and hierarchy

Authentication Certificate Signature Certificate

77

eID CA profile and hierarchy

Citizen CA CRL distribution point Citizen CA Authority Key identifier

88

eID CA profile and hierarchy

Citizen Certificates Authority Information access Citizen Certificates CDP

99

eID repository

eID CSP repository links:http://repository.eid.belgium.be is the eID CSP web sitehttp://crl.eid.belgium.behttp://certs.eid.belgium.behttp://status.eid.belgium.be

• Certificate Status Web Service: provide real time certificate status• Certificate Revocation List (CRL) Lookup Service

http://ocsp.eid.belgium.beldap.eid.belgium.be port 389

The new eID government web site:http://eid.belgium.be

• With link to Fedict and RRN web sites

Certipost eID web shophttp://www.eid-shop.be

1010

eID repository

1111

eID LDAP

eID LDAP is the CA public directory:

Accessible by using LDAP v2 on the host ldap.eid.belgium.be port

389 base dc=eid, dc=belgium, dc=be

1212

eID CRL/ ΔCRL

Used to validate certificates

Include information suchIssuer of the CRL

Type of signature applied on the CRL

Date and Time when the CRL is issued

Date and Time of the next CRL update

List of revoked certificates (Serial Number, Revocation date)

1313

Certificate revocation list profile

eID CRL/ ΔCRL

Version v2

Signature sha1RSA

Issuer <subject CA>

ThisUpdate <creation time>

NextUpdate <creation time> + 7 days

RevokedCertificates

UserCertificate <certificate serial number>

RevocationDate <revocation time>

CrlEntryExtensions

CRL Reason Code certificateHold(6) (for suspended certificates)Note: Otherwise NOT included!

CrlExtensions

Authority Key Identifier non-critical <subject key identifier CA>

CRL Number non-critical <The CA operator assigned unique number>

1414

Certificate revocation list profile

eID CRL/ ΔCRL

1515

Delta CRL profile

eID CRL/ ΔCRL

1616

eID CRL/ ΔCRL

Serial number

1000 0000 00001000 0000 00011000 0000 00021000 0000 0003

1000 0000 00051000 0000 00061000 0000 0007

Serial number

1000 0000 00001000 0000 00011000 0000 0002

t0 t1 (= t0 + 3h) t2 (= t1 + 3h) (= t0 + 6h)

Serial number

1000 0000 00001000 0000 00011000 0000 00021000 0000 00031000 0000 00041000 0000 0005

Serial number

1000 0000 00031000 0000 0004 (certificateHold)1000 0000 0005

Serial number

1000 0000 0004 (removeFromCrl)1000 0000 00061000 0000 0007

CR

L D

elt

a C

RL

CRL/Delta CRL process

1717

eID CRL/ ΔCRLCurrent CRL size for the Citizen CA 2004 is about 3,04 MB

Estimated entry per future CRL/ ΔCRL size is about 38 bytes / entry

CRL size for 16 000 000 citizen certificates: 580 MB Needs CRL splitting schema by generating several Citizen CA’s Each CA will issue its own CRL and ΔCRL

size issue !

3 options to mitigate it:

• Use ΔCRL

• Generate several CA certificates

• Use OCSP

1818

eID OCSP

The OCSP is OCSP V1 compliant (RFC2560).

Suspended certificates will be marked as revoked since the “Suspended” status is currently not supported by OCSP.

Good if the certificate is issued by the CA and if the certificate is valid

Revoked if the certificate is issued by the CA and the status of the certificate is revoked or the certificate is suspended

Unknown if the certificate is not issued by the CA

1919

eID OCSP

Applications or relying party

Citizen CA

OCSP responder

CRL

OCSP Client

Cert #123Alice

OCSP Request:Cert #123

Belgium Root CA

CA DB

Provide real-time status information

Decrease risk of using revoked certificates

Return status good, revoked or unknown

Use of OCSP URL from certificate to gain access to the responder

ΔCRLWeb status

2020

OCSP versus CRL/ΔCRL

Your application

(Offline)CertificateRevocationList

Online Certificate StatusProtocol

eID Validation Services

Back-office

Citizen

Citizen

2121

OCSP versus CRL/ΔCRL

  OCSP CRL/Delta CRL

Access method Online:          Transaction based relying on the OCSP server availability          About no delays between requests and answers          Gets the effective and current certificates status          Requesting service must be able to perform an online OCSP request

Offline:          Download of the last CRL/DeltaCRL before any validation          Local transaction           Not synchronised with the online status; maximum of 3 hours of delay if each DeltaCRL is fetched

Access protocol HTTP HTTP(s)/LDAP

Local storage needed NOVery limited as transaction based

YESNeed to download and store locally at least the last CRL/DeltaCRL;It is disk storage consuming;

Internet bandwidth LOW As transaction based

HIGHIt will require a high bandwidth for downloading CRL’s. As every eID citizen’s certificate is first suspended before being optionally activated large CRL file   Signed answer YES

Answers are signed by the OSCP responder private key

YESCRL and Delta CRL are signed by the issuing CA private key

2222

OCSP versus CRL/ΔCRL

E.g. eID OCSP validations services could be used daily in conjonction with CRL/ ΔCRL as back up

Choice between OCSP and CRL/ ΔCRL is depending on your business, on your risk assessment, …

Most probably a balance between the 2 protocols

2323

Thank You !