Method for issuing ic card storing encryption key information

Abstract

It is possible to issue an IC card storing unique encryption key information in such a manner that re-issuing is enabled and sufficient security can be assured. An IC card provider X delivers an IC card having a group code G(A) to a company A and an IC card having a group code G(B) to a company B. When a company staff α inputs a unique personal code P(α) and performs initialization, in the IC card, calculation is performed according to a predetermined algorithm using the P(α) and G(A). Data uniquely determined by the calculation is stored as encryption key information K(α) in the IC card. Even if the company staff α loses the IC card, it is possible to obtain the IC card having the same encryption key information K(α) as before by performing initialization again by using the IC card delivered by the IC card provider X.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for issuing IC cards storing encryption key information, and particularly relates to a method for respectively issuing a plurality of IC cards, each storing unique encryption key information, to specific individuals belonging to specific groups. BACKGROUND ART [0002] IC cards are used in various applications as portable information recording media of extremely high confidentiality and recently many companies distribute multifunctional IC cards, serving as company staff ID cards at the same time, to their respective company staff. There are also many examples, where such confidentiality is noted and an IC card is used as a storage medium for storing key data which is used to encrypt and decrypt information. Often in a general encryption method, a secret encryption key or encryption key table (here, these shall be referred to collectively as “encryption key information”) is used as a seed in an encryption algorithm. In a...

AI Technical Summary

Benefits of technology

[0040] With the present invention's method for issuing IC cards storing encryption key information, the encryption key information is prepared using the secret group code and the secret personal code in the interior of an IC card and is stored as it is in the IC card. Here, the secret group code is a code defined for a group to which an individual, to whom the IC card is issued, belongs, and this code can be put in the custody, for example, of a manager of an IC card provider. Meanwhile, the secret personal code is a code designated by the individual to whom the IC card is issued, and this code can be put in the custody of the individual him / herself. Because neither the secret group code nor the secret individual code is the encryption key information in itself, the encryption key information inside the IC card is maintained in a state of being stored without being known to anyone. When the IC card is lost or damaged by any chance, the IC card can be reissued because, by inputting the secret group code, kept in the custody of the manager, and the secret personal code, kept in the custody of the individual, into a new IC card, the same encryption key information can be prepared in the interior of the IC card again. The present invention thus enables an issuing process to be carried out in a mode enabling reissuing and yet enabling the ensuring of sufficient security in cases where plurality of IC cards, each storing unique encryption key information, are respectively issued to specific individuals belonging to specific groups.

Problems solved by technology

That is, the decryption cannot be performed as long as the secret encryption key information is not provided.

However for practical use, such an ideal method cannot be employed since there is a need to leave open a way of reissuing an IC card.

Thus when an IC card is lost or the IC card is damaged by any chance, unless an IC card storing the same encryption key information can be reissued, data that had been encrypted in the past can never be decrypted again.

However, in terms of practical use, problems of not being able to ensure sufficient security arise.

However, that a person who will commit an illicit act absolutely does not exist among company staff involved in an IC card issuing task cannot be guaranteed.

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