Universally Composable Adaptive Priced Oblivious Transfer
ثبت نشده
چکیده
An adaptive k-out-of-N Priced Oblivious Transfer (POT) scheme is a two-party protocol betweena vendor and a buyer. The vendor sells a set of messagesm1, . . .,mN with pricesp1, . . . ,pN . Ineach transfer phase i = 1, . . . , k, the buyer chooses a selection value σi ∈ {1, . . . ,N } and interactswith the vendor to buy messagemσi in such a way that the vendor does not learn σi and the buyerdoes not get any information about the other messages.We present a POT scheme secure under pairing-related assumptions in the standard model. Ourscheme is universally composable and thus, unlike previous results, preserves security when it isexecuted with multiple protocol instances that run concurrently in an adversarially controlled way.Furthermore, after an initialization phase of complexity O(N ), each transfer phase is optimal interms of rounds of communication and it has constant computational and communication cost. Toachieve these properties, we design the first efficient non-interactive proof of knowledge that a valuelies in a given interval we are aware of.
منابع مشابه
Universally Composable Adaptive Priced Oblivious Transfer
An adaptive k-out-of-N Priced Oblivious Transfer (POT) scheme is a two-party protocol between a vendor and a buyer. The vendor sells a set of messages m1, . . . ,mN with prices p1, . . . , pN . In each transfer phase i = 1, . . . , k, the buyer chooses a selection value σi ∈ {1, . . . ,N } and interacts with the vendor to buy message mσi in such a way that the vendor does not learn σi and the b...
متن کاملUniversally Composable Efficient Priced Oblivious Transfer from a Flexible Membership Encryption
Membership encryption is a newly developed cryptographic primitive that combines membership proof and encryption into an unified setting. This paper presents a new flexible membership encryption scheme which is provably secure and significantly more efficient than the previous scheme. Further we apply our proposed membership encryption to construct a round optimal 1-outof-n priced oblivious tra...
متن کاملUniversally Composable Adaptive Oblivious Transfer
In an oblivious transfer (OT) protocol, a Sender with messages M1, . . . ,MN and a Receiver with indices σ1, . . . , σk ∈ [1, N ] interact in such a way that at the end the Receiver obtains Mσ1 , . . . ,Mσk without learning anything about the other messages and the Sender does not learn anything about σ1, . . . , σk. In an adaptive protocol, the Receiver may obtain Mσi−1 before deciding on σi. ...
متن کاملOn Black-Box Complexity of Universally Composable Security in the CRS Model
In this work, we study the intrinsic complexity of black-box Universally Composable (UC) secure computation based on general assumptions. We present a thorough study in various corruption modelings while focusing on achieving security in the common reference string (CRS) model. Our results involve the following: • Static UC secure computation. Designing the first static UC secure oblivious tran...
متن کاملOptimistic Fair Priced Oblivious Transfer
Priced oblivious transfer (POT) is a two-party protocol between a vendor and a buyer in which the buyer purchases digital goods without the vendor learning what is bought. Although privacy properties are guaranteed, current schemes do not offer fair exchange. A malicious vendor can, e.g., prevent the buyer from retrieving the goods after receiving the payment, and a malicious buyer can also acc...
متن کامل