Input-Aware Equivocable Commitments and UC-secure Commitments With Atomic Exchanges

We define a new primitive, input-aware equivocable commitment, baring similar hardness assumptions as plaintext-aware encryption and featuring equivocability. We construct an actual input-aware equivocable commitment protocol, based on a flavor of Diffie-Hellman assumptions allowing adversarially chosen domain parameters. On a parallel front, and since our commitment is extractable and equivocable in a straight-line way, we show that our commitment enjoys UC-security, when atomic exchanges are available as a UC setup. We further compare our protocol and our UC setup with similar, existing ones (i.e., in terms of efficiency, assumptions needed, etc.). Finally, we show that cryptography becomes UC-realizable in a natural way when participants are able to have "close encounters" or when atomic exchanges can be enforced onto the communication.


Published in:
Provable Security, 8209, 121-138
Presented at:
7th International Conference on Provable Security (ProvSec), Melaka, Malaysia, October 23-25, 2013
Year:
2013
Publisher:
Springer
Laboratories:




 Record created 2013-10-28, last modified 2018-09-13

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