Design Aspects. by Olivier Delos. A work done jointly with Sylvie Lacroix (SEALED) and Ronny Bjones (Microsoft) Design - Introduction

Design Aspects by Olivier Delos

A work done jointly with Sylvie Lacroix (SEALED) and Ronny Bjones (Microsoft)

Design - Introduction • Goal • Advantages • Some selected requirements on Electronic Signature

eID “Voor een veilig gebruik van de electronische identiteitskaart op het internet” - Dinsdag 14 maart 2006

eID "Voor een veilig gebruik van de elektronische identiteitskaart op het internet"

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Design - Goal • To provide some requirements (vs guidance) on Application/Service Design in terms of usage of eID when related to the implementation of : – – – –

Electronic Signature (Strong) Authentication Data Capture Or a mix of these


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Design - Advantages • Implement legal & policy requirements • Stress on critical issues when implementing eID based Electronic Signatures, Authentication, or Data Capture • Increase level of trust in Application • Best practices • Check list for self-assessment as preparatory work for control or audit



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Design – Some requirements Electronic Signature • • • • • • •

ES Business context & eID context Secure development methods Security measures on developed system Signature creation process Signature Lifetime Signature Verification process Recommendation & Info to Signer


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Electronic Signature Business & eID contexts ?

Is it easy to implement an Electronic Signature ? ic ctron h Ele e ? ic h W atur Sign • E-mail footer • Advanced Electronic Signature • Qualified Electronic Signature • Other ? • Multiple signatures • Co-signature • Serial / Parallel • etc.

ness Busi h ic In wh ntext ? co • e-Mail • e-Contracting • e-Invoicing • e-Tendering • e-Government • Etc.

t& Wha rify ? v to e How

xtend ich e nt ? h w To me mmit or co • Data origin authentication & message integrity • Approval or agreement • Author or ownership • ...

roof ich p ? h w With ow long h & for



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Electronic Signature Business & eID contexts s cline A de ? C n e y! Citiz abilit any li

• Advanced ES • Qualified Certificate • SSCD

As long as it can be linked to the data to which they relate in such a manner that any subsequent change of the data is detectable

Qualified Signature ≡ Handwritten Signature

• Advanced ES • Authent° Certificate • SSCD

Advanced ES ≡ Signature with non deniable legal effect 7


Business & eID contexts • To Sign or not to sign ? There is ES and ES ! • In a e-Contracting context – – – –

Request Conditions Offer Acceptation

Qualified Signature ≡ Handwritten Signature

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Advanced ES ≡ Signature with non deniable legal effect

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• In a e-Invoicing context – Adding a legal signature to a (paper or electronic) invoice by the issuer would legally mean that the other party has paid (!!?) – But how to better guarantee data origin authen° & data integrity ?

• Use a Signature (Validation) Policy & make it clear for Signer & Verifier !! eID “Voor een veilig gebruik van de electronische identiteitskaart op het internet” - Dinsdag 14 maart 2006


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Electronic Signature Secure development & security •

Secure Development Methods & Model –

E.g., Capability Maturity Model (level 3 to 4) to avoid un-documented development, development with unclear behaviour and unclear security level

•

Auditable logging facilities (of any event on SCS)

•

State-of-the art security measures – – – –

Technology

Using latest managed software environments (e.g., Java, .Net) Using well-tested and reviewed implementation of standards Using (certified) ad-hoc cryptographic librairies Protection against malicious softwares (use PIN entry for each QES and close eID card after each QES, using secure viewers) Technology

– – –

Anti-virus, spyware protection, firewall Up-to date security fixes … eID “Voor een veilig gebruik van de electronische identiteitskaart op het internet” - Dinsdag 14 maart 2006


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Design – Electronic Signature Signature creation process •

Signer’s Document appearance – –

•

Signature Format vs Signature Lifetime – – – – –

•

WYSIWYS – secure viewers Protection against hidden information and code Basic ES or Explicit Policy ES ES-T: ES + Time Stamp Token or Time Mark ES-C: ES-T + Complete validation information ES-X: ES-T + extended validation information ES-A: ES-C or ES-X + extra TST or TM for long term archiving

Signature Attribute – – – – –

Signer’s Certificate Identifier Signature Policy Data Content Type Commitment Type Others like Signer’s role, location, time of signing, etc. eID “Voor een veilig gebruik van de electronische identiteitskaart op het internet” - Dinsdag 14 maart 2006


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Design – Electronic Signature Signature creation process •

Signer’s interface – – – – – – –

•

Consistent & Suitable for the task Conformity with user’s expectation Adequate status reports and error messages Non trivial invocation process Inactivity timeout Signer keeps control (SD, Attributes, PIN, etc.) Screen displays a minimum about signer’s info, etc.

Protection against threats – – – – –

Inappropriate signature (SD exist) Hidden elements in SD Unsecure communication between SCA and eID card Fake or impersonated SCA Incorrect or invalid certificate, etc.


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ES Business context & eID context Secure development methods Security measures on developed system Signature creation process Signature Lifetime Signature Verification process Recommendation & Info to Signer 15


Design – Electronic Signature Verification Process •

Collection of information for verification – – – –

•

Captured Data !

Signature verification process – – –

– –

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Signer’s Document Signature Format versus Lifetime Signature Attribute Certificate path building

Verify Certificate Policy & Qualified statement Certificate path construction and validation Verify Revocation status information (whole certificate path) ! Grace Period ! Time related verification (time-stamp or time-mark) Signature’s attribute (signer’s role, signature policy, etc.)

Signature verification output (

9X ? and proof format)



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Verification Process – Grace Period Time for the CA to process revocation request

Time for the CA to publish revocation status

T4

? T3

T5

T1

T2 No revocation information should have been issued in T5, and a revocation has been issued in T4 but T4 > T3, where: T1 = Time at which the ES is applied to the SD, T2 = Time at which either the ES is Time-stamped (or Time-marked) or Time at which the ES is received by the Verifier T3 = T2 + “Grace Period”, T4 = Certificate Revocation Time, T5 = Initial Verification Time. When T4 < or = T3, then the validation output status shall be “failed”. eID “Voor een veilig gebruik van de electronische identiteitskaart op het internet” - Dinsdag 14 maart 2006

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Electronic Signature Recommendation & Info to Signer

• Correct information should be presented to Signer – Legal requirements • e.g., Data has been captured (certificate)

– Information related to rights & duties linked to the usage of eID (see Certification Practice Statement) – Secure Viewer (WYSIWYS, no hidden codes, etc.) eID “Voor een veilig gebruik van de electronische identiteitskaart op het internet” - Dinsdag 14 maart 2006

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Design – Authentication • Overview



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Design – Authentication • Secure Development • Secure System • Authentication process – Recommendations to User – Authentication Policy

• Verification process – – – –

Certificate Policy & Issuer statement Certificate path construction & validation Revocation status information User’s attribute (if any)

• Trusted Path eID “Voor een veilig gebruik van de electronische identiteitskaart op het internet” - Dinsdag 14 maart 2006

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Design – Data Capture • Overview



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Design – Data Capture • Secure Development • Secure System • Data Capture Process – Recommendations to User – Data Capture Policy

• Captured Data Verification Process • Trusted Path – Should not perform Data Capture from a remote location but use certified info instead


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Design - Conclusion • Correct Design increases chance of correct application – Business requirements fulfilled – Legal & policy requirements fulfilled – Technical & security best practices – Trust level increased



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Contact Information • Sylvie Lacroix [email protected] • Olivier Delos [email protected]

• Ronny Bjones [email protected]



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Design Aspects. by Olivier Delos. A work done jointly with Sylvie Lacroix (SEALED) and Ronny Bjones (Microsoft) Design - Introduction

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