By introducing novel methods for robust protocol design, to substitute for costly zero-knowledge schemes, we are able to produce a mixing scheme with significantly lower costs of operation than all previously known such schemes. The scheme takes a list of ElGamal encrypted messages, and produces as output a permuted list of encryptions of the same plaintext messages, such that corresponding items of the input and output cannot be correlated. For reasonably large inputs, the cost per participating server and element to be mixed is less than 200 modular multiplications, which is almost two orders of magnitude faster than the most efficient previously known method. The scheme has the novel feature of not requiring the knowledge of a secret key corresponding to the public key used to encrypt the messages constituting the input to the mix-network.

Flash mixing

According to one general aspect, a method of managing a web browser extension by an apparatus may include executing, by a processor included by the apparatus, a web browser. The method may include installing on the apparatus, via the web browser, a web browser extension. In one embodiment, the web browser extension may include at least one web page configured to alter the functionality of the web browser, and a substantially unique identifier (UID) based upon a public encryption key. The method may further include launching, via the web browser, the web browser extension based upon the substantially unique identifier.

Web browser extensions

We present Millimix, a mix network that is highly efficient on small input batches. The construction is conceptually simple, and both robust and private in the face of collusion by any minority set of malicious players. Additionally, Millimix the feature of being publicly verifiable. In other words, the mixing operation yields a transcript that demonstrates correctness to a third party that the mix proceeded correctly.

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Millimix: Mixing in Small Batches

In a network device, a method for verified communication includes generating a network communication message using a selection of predetermined message elements having digital signatures generated with a private key. The network device generates a signature for the message by applying a homomorphic operation to the digital signatures of the selected predetermined message elements and to a one-time signature corresponding to a random number. The network device transmits the message in association with the signature for the message and the random number to at least one other network device.

System and method for message verification in broadcast and multicast networks

The present invention relates to a method and a system of securely computing a measure of similarity for at least two sets of data. A basic idea of the present invention is to securely compare two sets of encrypted data to determine whether the two sets of data resemble each other to a sufficient extent. If the measure of similarity complies with predetermined criteria, the two sets of data from which the encrypted sets of data originate are considered to be identical.

/pdf/securely-computing-a-similarity-measure-3b27v60zd3.pdf

Securely computing a similarity measure

A method for secure multiparty computation is disclosed In one embodiment, participants to a secure computation agree upon a function to be computed and a representation of the function as a circuit with at least one gate Logical tables are then generated for each gate A logical table includes all possible input and output values for the gate based on the function These input and output values are then encoded and the encoded tables are passed through a mix network, which generates a blinded table for each encoded logical table A blinded table corresponds to the encoded logical table except that its rows are randomly permuted and entries are encrypted After this initial blinding round, participants provide encryptions of their encoded secret inputs The participants then jointly compute the function of interest using the encrypted secret inputs and the representative circuit To simulate a gate therein, the participants compare the encrypted inputs to the gate with each encrypted input entry in the blinded table until a match is detected When a match is detected, the corresponding output entry in the matched row is taken to be the output of the gate This method of mixing and matching is performed in an identical manner for every gate in the circuit, irrespective of the layer in which it resides or the function being computed, until the output of the last gate is identified

Ari Juels

Papers

Mix and match: a new approach to secure multiparty computation