[BLR^{+}14] 
Semantically Secure OrderRevealing Encryption: MultiInput Functional Encryption Without Obfuscation
By Dan Boneh, Kevin Lewi, Mariana Raykova, Amit Sahai, Mark Zhandry, and Joe Zimmerman
[PDF]
[ePrint]

[SZ14] 
Obfuscating LowRank Matrix Branching Programs
By Amit Sahai and Mark Zhandry
[PDF]
[ePrint]
In this work, we seek to extend the capabilities of the “core obfuscator” from the work of Garg, Gentry, Halevi, Raykova, Sahai,
and Waters (FOCS 2013), and all subsequent works constructing generalpurpose obfuscators. This core obfuscator builds upon
approximate multilinear maps, and applies to matrix branching programs. All previous works, however, limited the applicability of
such core obfuscators to matrix branching programs where each matrix was of full rank. As we illustrate by example, this
limitation is quite problematic, and intuitively limits the core obfuscator to obfuscating matrix branching programs that cannot
“forget.” At a technical level, this limitation arises in previous work because all previous work relies on Kilian’s statistical
simulation theorem, which is false when applied to matrices not of full rank.
In our work, we build the first core
obfuscator that can apply to matrix branching programs where matrices can be of arbitrary rank. We prove security of our
obfuscator in the generic multilinear model, demonstrating a new proof technique that bypasses Kilian’s statistical simulation
theorem. Furthermore, our obfuscator achieves two other notable advances over previous work:
• Our construction allows for nonsquare matrices of arbitrary dimensions. We also show that this flexibility yields
concrete efficiency gains.
• Our construction allows for a single obfuscation to yield multiple bits of output. All previous work yielded only one bit
of output.
Our work leads to significant efficiency gains for obfuscation. Furthermore, our work can be applied to achieve efficiency gains
even in applications not directly using obfuscation.
@misc{SZ14, author = {Amit Sahai and Mark Zhandry}, title = {Obfuscating LowRank Matrix Branching Programs}, misc = {Full version available at \url{http://eprint.iacr.org/2014/773}}, year = {2014} }

[BZ14] 
Multiparty Key Exchange, Efficient Traitor Tracing, and More from Indistinguishability Obfuscation
By Dan Boneh and Mark Zhandry
In CRYPTO 2014
[PDF]
[ePrint]
[slides]
In this work, we show how to use indistinguishability obfuscation (iO) to build multiparty key exchange,
efficient broadcast encryption, and efficient traitor tracing. Our schemes enjoy several interesting
properties that have not been achievable before:
• Our multiparty noninteractive key exchange protocol does not require a trusted setup. Moreover,
the size of the published value from each user is independent of the total number of users.
• Our broadcast encryption schemes support distributed setup, where users choose their own
secret keys rather than be given secret keys by a trusted entity. The broadcast ciphertext size is
independent of the number of users.
• Our traitor tracing system is fully collusion resistant with short ciphertexts, secret keys,
and public key. Ciphertext size is logarithmic in the number of users and secret key size is independent
of the number of users. Our public key size is polylogarithmic in the number of users. The recent
functional encryption system of Garg, Gentry, Halevi, Raykova, Sahai, and Waters also leads to a traitor
tracing scheme with similar ciphertext and secret key size, but the construction in this paper is simpler
and more direct. These constructions resolve an open problem relating to differential privacy.
• Generalizing our traitor tracing system gives a private broadcast encryption scheme (where broadcast
ciphertexts reveal minimal information about the recipient set) with optimal size ciphertext.
Several of our proofs of security introduce new tools for proving security using indistinguishability obfuscation.
@inproceedings{BZ14, author = {Dan Boneh and Mark Zhandry}, title = {Multiparty Key Exchange, Efficient Traitor Tracing, and More from Indistinguishability Obfuscation}, booktitle = {Proceedings of CRYPTO 2014}, misc = {Full version available at \url{http://eprint.iacr.org/2013/642}}, year = {2014} }

[HJK^{+}14] 
How to Generate and use Universal Parameters
By Dennis Hofheinz, Tibor Jager, Dakshita Khurana, Amit Sahai, Brent Waters, and Mark Zhandry
[PDF]
[ePrint]
We introduce the notion of universal parameters as a method for generating the trusted parameters for many schemes from just
a single trusted setup. In such a scheme a trusted setup process will produce universal parameters U. These parameters can then
be combined with the description, d(·) of any particular cryptographic setup algorithm to produce parameters pd that can be used
by the cryptographic system associated with d. We give a solution in the random oracle model based on indistinguishability
obfuscation.
We demonstrate the versatility of universal parameters by showing how they give rise to applications such as
identitybased encryption and noninteractive identitybased key exchange. More generally, we observe that universal parameters
can also be seen as universal samplers, allowing a user to sample from arbitrary efficiently sampleable distributions.
@misc{HJKSWZ14, author = {Dennis Hofheinz and Tibor Jager and Dakshita Khurana and Amit Sahai and Brent Waters and Mark Zhandry}, title = {How to Generate and use Universal Parameters}, misc = {Full version available at \url{http://eprint.iacr.org/2014/507}}, year = {2014} }

[Zha14a] 
How to Avoid Obfuscation Using Witness PRFs
By Mark Zhandry
[PDF]
[ePrint]
Recently, program obfuscation has proven to be an extremely powerful tool and has been used to construct a variety of
cryptographic primitives with amazing properties. However, current candidate obfuscators are far from practical and
rely on unnatural hardness assumptions about multilinear maps. In this work, we bring several applications of obfuscation
closer to practice by showing that a weaker primitive called witness pseudorandom functions (witness PRFs) suffices.
Applications include multiparty key exchange without trusted setup, polynomiallymany hardcore bits for any oneway
function, and more. We then show how to instantiate witness PRFs from multilinear maps. Our witness PRFs are simpler and
more efficient than current obfuscation candidates, and involve very natural hardness assumptions about the underlying maps.
@misc{Zha14a, author = {Mark Zhandry}, title = {How to Avoid Obfuscation Using Witness PRFs}, misc = {Full version available at \url{http://eprint.iacr.org/2014/301}}, year = {2014} }

[ABG^{+}13] 
DifferingInputs Obfuscation and Applications
By Prabhanjan Ananth, Dan Boneh, Sanjam Garg, Amit Sahai, and Mark Zhandry
[PDF]
[ePrint]
