Scheme, system and equipment for inter-equipment authentication and key delivery

An equipment authentication and cryptographic communication system, comprising:

• user-end equipment, system-end equipment, and a key center for administrating authentication of equipment in said system, wherein;
• said key center is provided with a first system converter for generating user-end equipment secret information from user-end equipment information;
• said user-end equipment is provided with a first storage unit for storing said user-end equipment information provided by said key center, a second storage unit for storing said user-end equipment secret information, a first encryption unit, and a first decryption unit;
• and
• said system-end equipment is provided with a second system converter for generating said user-end equipment secret information by a system conversion of said user-end equipment information received from said user-end equipment, a second encryption unit, and a second decryption unit, said second system converter using an equivalent secret key cryptographic algorithm of the first system converter to generate said user-end equipment secret information from said received user-end equipment information,
• said user-end equipment and said system-end equipment share and utilize said user-end equipment secret information as a common key for encryption and decryption in said first encryption unit and said first decryption unit in said user-end equipment, and said second encryption unit and said second decryption unit in said system-end equipment,
• said user-end equipment further comprises a first random digit generator for generating a random digit, a second random digit generator for generating a random digit, a first combiner for combining a pair of random digit data according to a predetermined procedure, a first divider for dividing a combined pair of random digit data to reproduce original random digits prior to combining, a first common key generator for combining a pair of random digit data according to a predetermined procedure, and a first matching determination unit for determining if two random digit data match each other;
• and
• said system-end equipment further comprises a third random digit generator for generating a random digit, a fourth random digit generator for generating another random digit, a second combiner for combining a pair of random digit data according to a predetermined procedure, a second divider for dividing a combined pair of random digit data to reproduce original random digits prior to combining, a second common key generator for combining a pair of random digit data according to a predetermined procedure, and a second matching determination unit for determining if two random digit data match each other.

A method of equipment authentication and cryptographic communication for an equipment authentication and cryptographic communication system including user-end equipment, system-end equipment, and a key center for administrating authentication of equipment in said system, said method comprising the steps of:

• generating user-end equipment secret information from user-end equipment information in said key center;
• receiving said user-end equipment information and said user-end equipment secret information in said user-end equipment from said key center;
• receiving said user-end equipment information from said user-end equipment, and generating said user-end equipment secret information from said user-end equipment information received in said system-end equipment by a system conversion using an equivalent secret key cryptographic algorithm of said key center;
• using said user-end equipment secret information as a common key for encryption and decryption in both of said user-end equipment and said system-end equipment;
• generating a first random digit in said user-end equipment, and transmitting said first random digit to said system-end equipment;
• generating a second random digit in said system-end equipment, combining said second random digit and said first random digit received from said user-end equipment, encrypting combined data of said second random digit and said first random digit using said common key, and transmitting said encrypted data to said user-end equipment;
• decrypting said encrypted data received in said user-end equipment using said common key, and reproducing said first random digit and said second random digit by dividing decrypted data of said encrypted data received in said user-end equipment;
• determining in said user-end equipment if said first random digit reproduced in the preceding decryption step matches with another first random digit generated therein;
• generating a third random digit in said user-end equipment, combining said third random digit and said second random digit reproduced in the decryption step, encrypting combined data of said third random digit and said second random digit using said common key, and transmitting encrypted data of said combined data to said system-end equipment;
• generating a fourth random digit in said system-end equipment, and transmitting said fourth random digit to said user-end equipment;
• combining said fourth random digit received in said user-end equipment from said system-end equipment and said third random digit generated therein, encrypting combined data of said fourth random digit and said third random digit using said common key, and transmitting encrypted data of said combine data to said system-end equipment;
• decrypting said encrypted data received in said system-end equipment using said common key, and reproducing said third random digit and said fourth random digit by dividing decrypted data of said encrypted data received in said system-end equipment;
• and
• determining in said system-end equipment if said fourth random digit reproduced in the preceding decryption step matches with another fourth random digit generated therein.