7 votes
Accepted

Does CCA security imply perfect secrecy?

Perfect secrecy & [the traditional/standard definition of] CCA security are incompatible. Shannon's theorem says that if you want perfect secrecy, then the key needs to be longer than the total ...
Mikero's user avatar
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3 votes
Accepted

Perfect Secrecy other than One-time Pad

There is a famous result about perfect secrecy, usually called Shannon's theorem: If an encryption scheme has perfect secrecy, then $|\mathcal{K}| \ge |\mathcal{M}|$, where $\mathcal{K}$ is the set ...
Mikero's user avatar
  • 13.1k
1 vote

Perfect Secrecy other than One-time Pad

There's computational perfect secrecy and information-theoretic perfect secrecy, and OTP belongs to the latter. If it's well-known information-theoretic perfect secrecy that you seek and is no less ...
DannyNiu's user avatar
  • 9,080

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