PKI 2.0 – Light Certificate Infrastructure

  • Light Certificate Infrastructure allows to build advanced electronic signature services tailored to the needs of individuals.
  • Typical electronic signature infrastructure is based on certificates, which contain and confirm all the information that can be used for signature verification whereas the electronic signature itself and the process of signing stays uncontrolled.
  • PKI 2.0 shifts the accent from the Certification Services to Signature Services, allowing to provide services that are much more flexible and customized.
  • In PKI 2.0 the credibility of a electronic signature is guaranteed by aSignature Authority from the very moment of the signature creation.



  • The goal of building solutions based upon the Light Certificate is to deliver to the society a broadly used electronic signature services.
  • Basic PKI 2.0 services are available upon signing up to online service.
  • Electronic signature services can be managed and extended by additional security measures and additional information to confirm in the signing process.
  • A mutual trust in the signature is essential to ensure its growth. The provision of PKI 2.0 services for the signatory guarantees quality.

Advanced signature as a service

  • PKI 2.0 requires that every electronic signature is created in cooperation with a Signature Authority
  • The main feature of the concept is to maintain sole control on the signature creation process and to prevent the signature creation without the participation of the signatory.
  • Signature Authority controls signature creation and ensures the quality of the signature incorporating certificate verification as one of the steps of signature creation.



  • Light Certificate infrastructure is compatible to PKI 2.0 infrastructure which introduces a full set of services related to the electronic signature. Services are aimed to meet the needs of individuals.
  • Light certificate infrastructure is based on a fundamental assumption of PKI 2.0, that the electronic signature should be a service and is created in a way controlled by the Signature Authority.
  • The signatory uses the signature services via a Signature Portal, which provides necessary services and allows managing the services scope (signatory’s account)
  • The Portal provides clear set of mechanisms and low complexity of solution from user site.
  • For the signatory, Signature Portal can be provided as an independent service, or component of an system i.e. banking or corporate.


Light certificate

  • Light Certificate does not contain personal data.
  • The basic purpose of certificate is interconnection of signatory account with keys used for signature verification.
  • Certificate points to Signature Authority, which controls signing process and rights verification at signing time.
  • Positive signature verification using light certificate puts the Signature Authority in the role of signature quality guarantor.
  • Certificate does not contain any information about rights of signatory, controls used and information whether certificate is qualified or not – mentioned information is attached during signing process as attributes confirmed by Signature Authority.


Personal data on demand

  • Signatory decides which his or her personal data are confirmed at signing time.
  • The range of personal data included in signature verified using light certificate can be tailored to the purpose of signature.
  • Credibility of personal data is confirmed by Signature Authority during signing process.
  • Personal data are specific kind of PKI 2.0 signature attributes, which usage depends on their confirmation and controls required by signing process.


Signatory’s account management

  • Signatory can manage his or her electronic digital signature account by defining new certificates, attributes and controls in real time.
  • One signature account can possess many light certificates related to various keys.
  • Signatory defines attributes which can be used and verified during signing process.
  • Signatory defines additional for key usage and attributes usage.


Signature accountability

  • Every event related to the signing is recorded in secure audit by a Signature Authority.
  • Audit record is an independent piece of evidence confirming signature creation and can be used in the case of dispute.
  • Electronic signature created with audit record is considered to be additionally protected using non-cryptographic controls.
  • It is possible to create remote signature validation service relying upon signature audit log maintained by Signature Authority. The service can be considered as an control for extremely sensitive transactions.



  • Information which should be confirmed during signing process are attributes of a signatory account.
  • During signing process, a signatory can choose attributes which will be confirmed in signing process.
  • Attributes such as personal data may require verification prior to the usage in signing process. These attributes can be verified according to agreed policy by a Signature Authority similarly to identity verification performed by CSPs.
  • Attributes can be authorized online. This kind of authorization can be used for attributes which depends on external factors i.e. resources secured on bank account, signature insurance, or rights in identity management system.
  • Finally, electronic signature with „Q” attribute will be qualified signature equivalent.




  • Mechanism enables usage of various electronic signature controls.
  • Controls could be defined in management process.
  • Controls could be environment dependent and could be combined together (i.e. signing documents outside intranet requires additional token).
  • Usage of particular control could be dependent to place of signing, time of signing, type of electronic signature or method of authentication to the Signature Portal.

Control dependant attributes

  • System provides a possibility of defining different controls for every single attribute. It gives an opportunity to protect creation of an electronic signature containing extremely sensitive information (such as amount of transaction) with additional controls.
  • Usage of controls compensates the risk related to unauthorized use of key. Thus, it is possible to use od controls adequate to users’ needs.
  • With control dependent attributes it is possible to use the same key pair and certificate to create electronic signature, advanced electronic signature and qualified electronic signature. The type of signature is determined by attributes and controls used.

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