Verifiable Attribute-based Encryption

In this paper,we construct two veriable attribute-based encryption(VABE)schemes.One is with a single authority,and the other is with multi authorities.Not only our schemes are proved secure as the previous ABE schemes,they also provide a verication property.Adding the verication property has a few advantages:first,it allows the user to immediately check the correctness of the keys,if not,he only needs the authority to resend the corresponding shares,especially,in multi-authoritycase,if the key does not pass the check,the user only needs to ask the particular authority to resend its own part,without need to go to all the authorities,this saves a lot of time when error appears;second,if the keys pass the verication but the user still does not rightly decrypt out the message,something might be wrong with the attributes or ciphertexts,then,the user has to contact with the encryptor.We formalize the notion of VABE and prove our schemes in our model

Attribute Based Encryption with Verifiable Time Stamped Decryption

Numerous applications require expanded insurance of private information including access control strategies that are cryptographically authorized. A promising utilization of ABE is adaptable get to control of scrambled information put away in the cloud, utilizing access polices and credited traits related with private keys and ciphertexts. Productivity disadvantages of the current ABE plans is that unscrambling includes costly matching operations and the quantity of such operations develops with the intricacy of the get to approach. The public key generation relying upon the properties of the predetermined content to be encrypted, that will create numerous keys to be utilized to scramble or unscramble the information. Extra private key to be included is the server time stamping with the encryption key to guarantee that the data should not be recovered after particular timeframe. The accompanying paper is depicting a strategies showing how to apply those technique safely and effectively to manage secret data circulated over capacity organize. Security and execution examination demonstrates the proposed plans are provably secure and exceptionally effective

Publicly-Verifiable Deletion via Target-Collapsing Functions

We build quantum cryptosystems that support publicly-verifiable deletion from standard cryptographic assumptions. We introduce target-collapsing as a weakening of collapsing for hash functions, analogous to how second preimage resistance weakens collision resistance; that is, target-collapsing requires indistinguishability between superpositions and mixtures of preimages of an honestly sampled image. We show that target-collapsing hashes enable publicly-verifiable deletion (PVD), proving conjectures from [Poremba, ITCS'23] and demonstrating that the Dual-Regev encryption (and corresponding fully homomorphic encryption) schemes support PVD under the LWE assumption. We further build on this framework to obtain a variety of primitives supporting publicly-verifiable deletion from weak cryptographic assumptions, including: - Commitments with PVD assuming the existence of injective one-way functions, or more generally, almost-regular one-way functions. Along the way, we demonstrate that (variants of) target-collapsing hashes can be built from almost-regular one-way functions. - Public-key encryption with PVD assuming trapdoored variants of injective (or almost-regular) one-way functions. We also demonstrate that the encryption scheme of [Hhan, Morimae, and Yamakawa, Eurocrypt'23] based on pseudorandom group actions has PVD. - $X$ with PVD for $X \in \{$attribute-based encryption, quantum fully-homomorphic encryption, witness encryption, time-revocable encryption$\}$, assuming $X$ and trapdoored variants of injective (or almost-regular) one-way functions.Comment: 52 page

Attribute-based encryption with verifiable outsourced decryption

Ministry of Education, Singapore under its Academic Research Funding Tier 1; Singapore Management University; Agency for Science, Technology and Research (A*STAR) SERC Gran

Publicly Verifiable Deletion from Minimal Assumptions

We present a general compiler to add the publicly verifiable deletion property for various cryptographic primitives including public key encryption, attribute-based encryption, and quantum fully homomorphic encryption. Our compiler only uses one-way functions, or more generally hard quantum planted problems for NP, which are implied by one-way functions. It relies on minimal assumptions and enables us to add the publicly verifiable deletion property with no additional assumption for the above primitives. Previously, such a compiler needs additional assumptions such as injective trapdoor one-way functions or pseudorandom group actions [Bartusek-Khurana-Poremba, ePrint:2023/370]. Technically, we upgrade an existing compiler for privately verifiable deletion [Bartusek-Khurana, ePrint:2022/1178] to achieve publicly verifiable deletion by using digital signatures