[Cryptography] End-to-End, One-to-Many, Encryption Question

[Kent Borg]

On 06/12/2014 06:50 AM, Ben Laurie wrote:
> All symmetric crypto algorithms need to have keys that are not a 
> group, or there is a meet-in-the-middle attack available. 

Dang, that makes sense.

But, as I am trying to "secure" data in the cloud, instead of just 
throwing up my hands, maybe I want to use an inferior algorithm that 
*is* a group...? Nah, then I am getting close to inventing my own crypto 
algorithms.

I'll have to think about my problem definition more, dig through my 
memory of available crypto primitives, and see if I can find another 
approach.

But people should be asking related questions more. The cloud is a cool 
thing, yet end-to-end encryption is the responsible approach, and there 
is a contradiction in the two.

Thanks for all the answers,

-kb, the Kent who will have to keep his eye open for progress in 
homomorphic encryption.