[Cryptography] Trapdoor symmetric key
iang at iang.org
Sun Sep 8 13:31:13 EDT 2013
On 8/09/13 16:42 PM, Phillip Hallam-Baker wrote:
> Two caveats on the commentary about a symmetric key algorithm with a
> trapdoor being a public key algorithm.
> 1) The trapdoor need not be a good public key algorithm, it can be
> flawed in ways that would make it unsuited for use as a public key
> algorithm. For instance being able to compute the private key from the
> public or deduce the private key from multiple messages.
> 2) The trapdoor need not be a perfect decrypt. A trapdoor that reduced
> the search space for brute force search from 128 bits to 64 or only
> worked on some messages would be enough leverage for intercept purposes
> but make it useless as a public key system.
Thanks. This far better explains the conundrum. There is a big
difference between a conceptual public key algorithm, and one that is
actually good enough to compete with the ones we typically use.
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