FOR INFORMATION October 16, 1998

NTT Develops Super-Multipurpose Smart Card

Nippon Telegraph and Telephone Corporation (NTT) has developed a Super-Multipurpose Smart Card that has a circuit to deal with multiple encryption methods and a large-scale nonvolatile erasable memory (memory that does not vanish when the power supply is cut off) of 512 kB, which is more than 10 times larger than the present memory. The smart card can be used for electronic money transactions and various services involving the distribution of multimedia information. The card can be used for a wide variety of applications that formerly required the use of individual cards (see figure). It also features a secure file management function, an anti-virus function and a function to download programs and data to handle the loading of various application programs, and enable the writing-in and rewriting of data. NTT will develop new IC card application systems using the new card. Development Background Compared to conventional magnetic cards, IC cards boast superior functions, performance and security. In particular, so-called "smart" cards, which have a CPU imbedded within them, can be used for many different purposes by loading application programs into them. The smart card featuring a coprocessor*1 is particularly well suited to electronic commerce since it can deal with encryption and authentication at high speed. If smart cards are to proliferate in the future, they will have to be able to handle multiple applications. However, first-generation smart cards, which had coprocessors in them, were hard-pressed to deal with multiple applications since only certain encryption and authentication methods could be used in them. They also were handicapped by a small memory capacity and slow input/output interface speed. By making full use of LSI technology as well as encryption and authentication technology, NTT has developed, and is now testing, a card that boasts multiple functions. Characteristics of the Super-Multipurpose Smart Card (see chart) 1. Development of coprocessor that deals with multiple encryption and authentication methods NTT developed the coprocessor of the card so it can deal with RSA method*2, the method relied on by most smart card coprocessors as well as elliptic curve encryption method*3 and NTT's original ESIGN*4. Accordingly, in case of emergencies, security can be obtained without interrupting service by changing encryption and authentication methods. 2. High Expandability by Adopting Flash Memory for Nonvolatile Erasable Memory Former smart cards used EEPROM*5 for nonvolatile erasable memory, but it is difficult to enlarge its scale, so it could only have a memory volume of 8 to 16 kB. As a result, most part of application programs, OS and input/output interfaces were loaded into ROMs, which prevented rewriting later on. This was a major reason that inhibited the card's expandability. This card adopts a flash memory*6, which is suited for enlarging the scale of nonvolatile erasable memory. This realizes a large volume of 512 kB, and enables one card to take over the functions of multiple cards. Also, this memory enables the addition of application programs and updated versions through the network. 3. High-Speed and High-Function Input/Output Interface This card enables high-speed input/output and rewriting of large volume and important data with the use of large-scale nonvolatile erasable memory. The input/output interface of this card is compatible with the ISO7816-3,-4*7, which is generally being used on earlier smart cards. Also, it is highly secure and practical, with a maximum transmission speed of 76 kbps, a program download function, anti-virus function and file management security function. Future NTT will work on enlarging the scale of flash memory, in addition to the card's speed and the function capabilities of the input/output interface. The firm also plans to continue its R&D efforts in order to improve the various functions and quality of the Super-Multipurpose Smart Card. Notes: *1 Coprocessor IC cards conduct integral calculations on numbers exceeding 300 digits of the decimal system for the purpose of data encryption/decryption and to create and verify signatures. Coprocessor is the calculation circuit for encryption and authentication that aids the CPU's ability to handle high-speed calculations and to do so promptly. *2 RSA method This is the main public encryption method. It is mainly used to transmit key data safely. Also, it can be used to confirm user identities via digital signature. The difficulty of deciphering depends on the difficulty of factoring large-digit numbers. *3 Elliptic curve encryption method This is a general term for encryption methods that is based on an elliptic curve. It has the characteristic of a more difficult decryption than the RSA method, even though it has shorter key length. At present, 160 key length, which is related to safety strength, equates with about 1000 bits of RSA method. Since it can secure safety with less data, it is expected to become a method for advancing next-generation security. *4 ESIGN This is a digital signature method developed by NTT. As with the RSA method, the difficulty of decrypting depends on the difficulty of factoring. Its main characteristic is the speed (10 to 100 times faster than RSA) with which it produces the digital signature. *5 EEPROM (Electric Erasable Programmable Read-Only Memory) Generally, ROMs cannot be rewritten, but EEPROM is a ROM whose data can be eliminated and changed electronically. *6 Flash Memory A type of EEPROM whose contents may be eliminated electronically. Elimination of every memory block is possible. It is suited to scale enlargement because its construction is simple with 1 device per 1 bit. *7 ISO7816-3,-4 This is a standard for contact-type IC cards, which has been devised by the International Organization for Standardization (ISO). Part 3 regulates the electronic signal and transmission protocol between the external terminal and IC cards as the interface conditions, and part 4 regulates the interface commands and parameters and the utilization ways of IC cards for international distribution.

Attachment - Figure   Construction and Superiority of Super-Multipurpose Smart Card - Chart   Main Function and Qualities of the Super-multipurpose Smart Card

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