Digital Stamps of Companies

Tarvi MartensSK, Estonia

Background

• Estonia is a country with fully deployed Public Key Infrastructure (ID-card) allowing:• Secure authentication to e-services• Digital signing

• Digital signatures is part of everyday’s life:• Common Signature System is used in all sectors• People share understanding of “what is digitally signed

file”

Signature is Personal

• There is no “company signatures” in the paper

• Notion of “Qualified Signatures” in digital world refers to digital signature created by physical person• “Qualified Signature” == “Advanced Electronic

Signature” (Directive 1999/93/EC) created with “Qualified Certificate” (Annex I)

The Problem

• People are seeking for company dimension in signed documents• Is this document signed behalf of a company?• How would I know whether the signatory works

for this organization?• Was the signatory eligible to sign such a

document?

Paper World

rubber stamp

claimed role,signature,name

letterhead

Security of paper ?

• Letterhead• Easy to copy, steal etc.

• Rubber stamp• Nobody knows who has access to it in the company

• Claimed role• Hard to verify

... but (for some funny reasons) all of this still gives some confidence

Solution for the Digital World

• Digital Stamps• Technically similar to digital signatures• Created with certificates issued to organizational entities• Stamping Policy refers to digital stamp certificate and

is digitally signed by authorized signer

Documenttext

Digital Stamp Digital Signature

StampingPolicy

Stamping Policy

• Describes restrictions for using the stamp:• Area of use• Type of applicable documents for this stamp• Person(s) eligible to stamp• Automatic vs manual stamping• Whether digital signature is needed in addition to the stamp• Security measures taken to protect private key for stamping• ...

Two Basic Types

• “Signed and stamped”• Represents official

document binded to company

• “Stamped”• Usually automatically• Creates evidence in

automated way

Documenttext

Digital Stamp

Digital Signature

Documenttext

Digital Stamp

Example Applications

• Immediate confirmation of retrieval of money transfer order in Internet banking• Proof to show to your business partner

• Digitally stamped legal proceedings• Stamping of query answer from official

registers• E-invoicing (ref. 2001/115/EC)• ...

Benefits

• Legal leap from “what I saw in the screen” to “proof that the system produced this data at that time”

• Big step towards automation• company stamp can replace signature in many

cases signature is required by law today• Real birth of “electronic certificates” like

birth certificate, marriage certificate, university diplomas,...

Current State of Deployment

• Digital stamps are used for several years in banking applications

• Estonia is going to legalize digital stamps by including the concept in Digital Signature Law

• Number e-government solutions are lined up to make use of digital stamping

Thank You!

tarvi@sk.ee