The card provides strong security against traditional outsider attacks, but unfortunately has not been designed with privacy in mind. In fact, it features one of the worst privacy designs imaginable. Two glaring problems:
The citizen certificates on each ID chipcard contain the cardholder’s name and RRN (the œrijksregistratienummer,” a single government-wide identification number for each natural person). The name and RRN are disclosed whenever a card is used at a relying party. The RRN (which has a simple structure based on the citizen’s birthday) serves as the key to numerous databases containing citizen information; on the basis of this number, all cardholder actions and movements with the eID chipcard can be electronically traced and linked (not merely by the government itself!).
The eID card specifies the following information, both visibly on the card itself and stored within the card’s chip: cardholder’s photo, surname and first names, gender, nationality, place and date of birth, signature, RRN, and the validity period of the card. In addition, the chip also stores the cardholder’s current address. Some of this information is privacy-sensitive, yet the cardholder has no control over its disclosure. (Historically, this is the same information as has always been on Belgium identity cards, and so arguably this does not constitute a reduction in privacy; however, in most countries around the world an information-rich national identity card would not pass in the first place.)
The privacy problems do not stop here. Each eID chip contains two X.509v3 identity certificates (each specifying the citizen’s name and RRN number, one for authentication and one for digital signing), as well as a basic signature key to authenticate the card with respect to the RRN. The certificates and public keys, which are assigned by the central issuing authority, by themselves serve as “omni-directional” identifiers that are globally unique. For a detailed account on the various privacy problems caused by this use of PKI, see, for instance, here.