Questions tagged [cca1]

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How can I understand the gap between CPA and CCA1?

I have read lots of books about CPA,CCA1,CCA2. I understand how to get an example satisfies CPA but not CCA2. However, I can't find such a scheme which is CPA but not CCA1. What is the extra advantage by lunch attack?
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How decode works in CCA1 scheme based on MP12 construction?

In Section 6.3 from MP12 we have that $encode(m) = Sm$, for $S$ any basis of $\Lambda(G^t)$. Then I have: $S = \begin{pmatrix} 1 & 2 & 4 & 8 & 16 & 32 & 64 & 128 & 256\\ 2 & 4 & 8 & 16 & 32 & 64 & 128 & 256 & 0\\ 4 & 8 & 16 & 32 & 64 & 128 & 256 & 0…
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Is there a LWE based public-key encryption scheme which is CCA1-secure?

Is there a lattice based PKE which is IND-CCA1 secure? Actually I am only familiar with LWE and SIS. So I want to know that what the IND-CCA1-secure LWE based PKE scheme looks like?
Blanco
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