eID is an electronic identification that is a solutions of citizens and organizations, accessing services by banks, government authorities and other companies. Many service providers give users the option to sign electronic documents with a digital signature (non-repudiation). A strong eID is based on PKI and certificates. Common Access Card is one form of eID, which is a physical identity card with a chip that carries the keys and certificates in a secure way and enables the card to be used for online and offline personal identification, authentication or signing. The card may be used for online authentication for e-government applications. An electronic signature, provided by a private company, may also be stored on the chip and act as an eID.