Data processing: financial – business practice – management – or co – Business processing using cryptography – Secure transaction
Reexamination Certificate
2006-03-14
2006-03-14
Trammell, James P. (Department: 3621)
Data processing: financial, business practice, management, or co
Business processing using cryptography
Secure transaction
C705S078000, C713S153000, C713S154000
Reexamination Certificate
active
07013295
ABSTRACT:
Purchase of information items from a merchant over the Internet or other network is implemented so as to ensure that the merchant is unable to identify the particular information item(s) purchased by a user. The user when considering purchase of a given information item is permitted to access a corresponding signed ciphertext of that item. The signed ciphertext in an illustrative embodiment includes a first ciphertext portion in the form of a symmetric key encrypted using a public key associated with the merchant, a second ciphertext portion corresponding to the information item encrypted using the symmetric key, an unencrypted description of the information item, and a tag corresponding to a signature. The user requests purchase of the information item by sending a blinded version of the first ciphertext portion to a payment server along with an appropriate payment. The payment server decrypts the blinded version of the first ciphertext portion and returns the resulting symmetric key to the user. The user then utilizes the symmetric key to decrypt the second ciphertext portion so as to obtain the desired information item. The decrypting operation performed by the payment server may be implemented using at least part of a set of multiple rounds, with the user providing a blinded ciphertext and receiving a corresponding decryption result for each of the rounds.
REFERENCES:
patent: 4759063 (1988-07-01), Chaum
patent: 5420926 (1995-05-01), Low et al.
patent: 5557518 (1996-09-01), Rosen
patent: 5615269 (1997-03-01), Micali
patent: 5629982 (1997-05-01), Micali
patent: 5715314 (1998-02-01), Payne et al.
patent: 5754656 (1998-05-01), Nishioka et al.
patent: 6049613 (2000-04-01), Jakobsson
patent: 6275936 (2001-08-01), Kyojima et al.
patent: 6396928 (2002-05-01), Zheng
Z. A. Ramzan, “Group Blind Digital Signatures: Theory and Applications,” MIT, May 1999.
T. ElGamal, “A Public Key Cryptosystem and a Signature Scheme Based on Discrete Logarithms,” IEEE Transactions on Information Theory, vol. IT-31, pp. 469-472, 1985.
C.P. Schnorr, “Efficient Signature Generation by Smart Cards,” Journal of Cryptology, pp. 161-174, 1981.
M. Jakobsson, “A Practical Mix,” Eurocrypt '98, LNCS 1403, pp. 448-461, 1998.
Jakobsson Bjorn Markus
Schnorr Claus Peter
Bayat Bradley
Lucent Technologies - Inc.
Trammell James P.
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