Data generating apparatus and data verifying apparatus
First Claim
1. A data generating apparatus, comprising:
- a receiver that receives initial data and extracts first data and second data from the initial data;
a key generation data memory unit that holds the second data;
an encrypting key generation unit comprising a one-way function that generates an encrypting key from second data stored in the key generation data memory unit;
an encryptor that encrypts the first data with the encrypting key generated by the encrypting key generation unit;
a previous key memory unit that holds a previous key; and
a sender that generates final data including at least one of the result of encrypting by the encryptor and the second data stored in the key generation data memory unit,wherein the encrypting key generation unit also uses the previous key stored in the previous key memory unit in generating the encrypting key.
1 Assignment
0 Petitions
Accused Products
Abstract
Integrity of data is to be ensured in a simple manner. A data verifier generates a signature generation request from data to be signed and signature request time, and sends the request to a data generator. The data generator extracts the data to be signed from the signature generation request, and its signature generation unit generates a signature for the data. A key generation unit generates a key from a previous key, the signature request time in the signature generation request, and the identifier of the data generator, and an encryptor encrypts the signature. After that, the encrypted signature and the like are returned to the data verifier, which generates a decrypting key with a key generation unit from the previous key, the signature request time, and the identifier of the data generator, then extracts an encrypted signature, and decrypts it with a decryptor. A signature verification unit checks whether or not the result of decrypting is the correct signature.
-
Citations
26 Claims
-
1. A data generating apparatus, comprising:
-
a receiver that receives initial data and extracts first data and second data from the initial data; a key generation data memory unit that holds the second data; an encrypting key generation unit comprising a one-way function that generates an encrypting key from second data stored in the key generation data memory unit; an encryptor that encrypts the first data with the encrypting key generated by the encrypting key generation unit; a previous key memory unit that holds a previous key; and a sender that generates final data including at least one of the result of encrypting by the encryptor and the second data stored in the key generation data memory unit, wherein the encrypting key generation unit also uses the previous key stored in the previous key memory unit in generating the encrypting key. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A data generating method comprising the steps of:
-
receiving initial data and extracting first data and second data from the initial data; generating an encrypting key from the second data using a one-way function; encrypting the first data with the encrypting key, the first data capable of being checked whether it includes a prescribed characteristic; and generating final data including at least one of the second data and the encrypted first data, wherein the encrypting key is also generated from a previous key stored in a previous key memory unit.
-
-
9. A data verifying apparatus, comprising:
-
a receiver that receives initial data and extracts first data and second data from the initial data; a key generation data memory unit that holds the second data; a decrypting key generation unit comprising a one-way function that generates a decrypting key from the second data stored in the key generation data memory unit; a decryptor that decrypts the first data with the decrypting key generated by the decrypting key generation unit; a verification unit that checks whether the first data decrypted by the decryptor has a prescribed characteristic and checks whether the decrypted first data is a result of decrypting prescribed data with a prescribed decrypting key; and a previous key memory unit that holds a previous key, wherein the decrypting key generation unit, in generating a decrypting key, also uses the previous key stored in the previous key memory unit. - View Dependent Claims (10, 11, 12, 13, 14)
-
-
15. A data verifying method comprising the steps of:
-
receiving initial data and extracting first data and second data from the initial data; generating a decrypting key from second data using a one-way function; decrypting first data with the decrypting key; and checking whether a result of decrypting includes a prescribed characteristic, wherein the second data is also generated from a previous key stored in a previous key memory unit.
-
-
16. A data processing apparatus comprising a data generating apparatus and a data verifying apparatus for verifying the integrity of encrypted data generated by the data generating apparatus, wherein:
-
the data verifying apparatus further comprises; a receiver that receives the encrypted data from the data generating apparatus; a reference value data memory unit that holds first data; a first key generation data memory unit that holds second data; a decrypting key generation unit comprising a one-way function that generates a decrypting key from the second data stored in the first key generation data memory unit; a decryptor that decrypts the encrypted data received from the data generating apparatus with the decrypting key generated by the decrypting key generation unit; and a verification unit that checks whether the data decrypted by the decryptor has a prescribed relationship with respect to integrity with the first data stored in the reference value data memory unit, and the data generating apparatus further comprises; a receiver that receives the first data from the data verifying apparatus and that generates third data from the first data; a second key generation data unit that holds fourth data; an encrypting key generation unit that comprises a one-way function for generating an encrypting key from the fourth data stored in the second key generation data memory unit; and an encryptor that encrypts the third data with the encrypting key generated by the encrypting key generation unit; and a sender that sends the encrypted third data to the data verifying apparatus. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
-
Specification