Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [proxy-re-encryption]

a type of public-key encryption scheme that allows to transform ciphertexts encrypted under Alice's public key into ciphertexts decryptable by Bob

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Can we proxy-re-encrypt using homomorphic encryption schemes?

Homomorphic encryption schemes are PKE schemes with an additional special method Evaluate. The Evaluate method takes input any function (as boolean circuit) and encrypted inputs of the function and evaluates the circuit. The results of such…
sashank
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Is there an encyption scheme that combines additive homomorphism with ability to proxy re-encrypt?

Is there an encyption scheme that combines additive homomorphism with ability to proxy re-encrypt? I've tried digging around on the Internet but haven't found anything conclusive on the topic.
Martin Sustrik
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Can RSA re-encrypt a message without decrypting it?

The goal of this question is to allow a server/proxy to forward an encrypted message without being able to read it with this procedure being transparent to the original sender and receiver. Assume we have Admin RSA Keys $(e,d,n)$ and Bob RSA Keys…
bitmask
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Multiparty dataset intersection count

Typically, Private Set Intersection (PSI) protocols let you learn the subset of items on each party's dataset that are in the intersection. The problem in this case is a relaxation of these kind of constructions. I would like to learn only the…
DaWNFoRCe
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Proxy Re-Encryption with provable re-encryption target

Suppose Alice has encrypted some plaintext $P$ to Bob. Bob wishes to re-encrypt this information to Charlie via proxy, in such a manner that: The proxy cannot obtain $P$ The proxy can prove that Bob has provided a valid re-encryption key, meaning…
Dr. John A Zoidberg
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How useful is proxy re-encryption if we end up needing a symmetric key?

I'm trying to design a system using proxy re-encryption (PRE) to allow the sharing of data between a user (delegator) and other users he delegates access to (delegatees). The goal is to use a PRE scheme to prevent the sharing of the delegator's…
mcansado
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ElGamal proxy re-encryption

I wrote an algorithm to implement a suggestion in a paper by Ivan and Dodis to convert a regular ElGamal encryption scheme into a proxy re-encryption one (it's at page 6, left column of this but I asked a question related to it on SO where you can…
mcansado
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ElGamal-based BBS proxy re-encryption implementation?

are there any available tools/libraries that implement the idea of EIGamal-based proxy re-encryption scheme shown below? Preferably in Golang. Thank you! Source of this picture: https://www.cs.jhu.edu/~susan/600.641/scribes/lecture17.pdf
Leo
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Data Security and Encryption

I have a research paper on data security using proxy re-encryption, and I need to provide an answer to a reviewer's comment. However, I have no idea on what to do or how to answer it. The security analysis of the proposed method is based on…
Kwame
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How can I use two different public keys with the same private key for fully homomorphic encryption?

I am pretty new to cryptography. Recently I run into this question where I have two different public keys with the same private key, and I need them for fully homomorphic encryption. Let's say messages from party $A$ and party $B$ are encrypted by…
Jimmy
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DES decryption of the homomorphic encryption ciphertext

I implemented an application using partial homomorphic encryption for outsourced computations. To get an efficient bandwidth, I am thinking to apply (DES) symmetric algorithm to encrypt the message instead of HE before uploading it to the cloud. Can…
Maka
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Can Paillier ,RSA or any other schemes be used for universal re-encryption like elGamal?

ElGamal, RSA, and Paillier cryptosystem have homomorphic property, and can be used fro re-encryption purposes. I want to use the encryption to re-encrypt ciphertext(as in proxy re-encryption but differently/different scenario / may be like…
abbasi_ahsan
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Securely rekey/re-encrypt AES-encrypted file

Suppose I have a big file encrypted using AES (any mode you want) with key kA. I'd like to give an untrusted proxy a kA->kB "conversion key" so that it re-encodes the file from kA to kB without learning the contents of the file or any of the…
Ark-kun
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Why is a proxy needed in proxy re-encryption?

Context Here's the usual proxy re-encryption scenario: Alice, with key pair $(pk_a, sk_a)$ encrypts a message $m$, producing $c = encrypt(pk_a, m)$ Alice saves $c$ on an untrusted storge provider (Dropbox, IPFS, etc..) Bob, with the key pair…
Fedma
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Is it possible to delegate re-encryption key generation?

In a non-interactive proxy re-encryption scheme, Alice, with the key pair $(pk_a, sk_a)$, needs to issue a re-encryption key $re_{a\rightarrow b}$ once she wants to share her secret message with Bob, with key pair $(pk_b, sk_b)$. In other words,…
Fedma
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