Hmm, I am not keen on the term "Hybrid" here at all. Note that nowhere in the msdn reference used to justify the answer does the word "hybrid" appear.
I guess the question is whats the difference between using both Symmetric and Asymmetric key processing and using a "Hybrid" of both? (these were two different answers offered on the question)
A hybrid of two techniques is not the same as a "combination" of two techniques. A combination implies that both techniques are used fully in conjunction, whereas a hybrid implies that the elements of one of the techniques have been partly replaced with one or more elements of the other. This is what a genetic hybrid is and where the term comes from.
Although I am not an expert in Cryptography, but I am familiar with the mathematical underpinnings and the implementation elements of both and I do not think that a hybridization of these two techniques is even mathematically possible, let alone cryptographically sound. If so, then someone should publish a paper on it because it would be seriously big news in the community.
To the best of my knowledge, Symmetric and Asymmetric techniques are only ever used in combination and are never hybridized.
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