Questions tagged [hashed-elgamal]

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Source of encryption scheme used in blockchain based IoT

I've found the following encryption scheme UserA: $$sk_A, pk_A = sk_A \cdot G$$ UserB: $$sk_B, pk_B = sk_B \cdot G$$ Enc: UserA $$u \in \mathbb{Z}_q^* \\ Y = u \cdot pk_B \\ S = H(U) \oplus m \\ C = (...
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Using GP/PARI how would you solve this randomised Elgamal question?

I know how to solve this question manually, but I don't know how to solve it using the program gp/pari. It is based on randomised Elgamal Let p = 739. Given the following ciphertext of some message m1 ...
Sarah's user avatar
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Why Bellare-Micali Oblivious Transfer Construction requires ElGamal with hashed key?

The idea of the Bellare-Micali Oblivious Transfer Constructions is the following: Informally, the receiver is required to generate two public keys $y_b$, $y_{b-1}$ such that it knows only the secret ...
Lorenzo's user avatar
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Understanding ElGamal encryption for a Mental Poker Case

I am looking to understand ElGamal encryption as it is used in a specic context described below. I am interested in creating a practical form of Mental Poker for games other than poker developed by ...
Mercure's user avatar
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Elgamal test vectors

I know that Elgamal algorithms have fallen out of fashion, and they are not included in any widespread cryptographic standard nowadays. However, they are still present in several popular crypto ...
SquareRootOfTwentyThree's user avatar
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3 answers
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Malleability of ElGamal and Hashed ElGamal

Question: Suppose A encrypts a number $x$ which indicates her bid on a contract, using ElGamal encryption. Say that the encryption of $x$ produces a ciphertext $c$. Explain how E can modify $c$ to ...
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