# Question about the fundamental security of MPC

**URL:** <https://forum.scrt.network/t/question-about-the-fundamental-security-of-mpc/453>\
**Category:** Uncategorized\
**Created:** [November 12, 2018, 1:25pm UTC](https://forum.scrt.network/t/question-about-the-fundamental-security-of-mpc/453 "2018-11-12T13:25:52Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Avret](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.scrt.network/avret/32/603_2.png) [@Avret](https://forum.scrt.network/u/Avret)\
**Post date:** [November 12, 2018, 1:25pm UTC](https://forum.scrt.network/t/question-about-the-fundamental-security-of-mpc/453/1 "2018-11-12T13:25:52Z")

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could you use a Dark DAO-like paradigm to break MPC-based computations?

everyone sends their share to an SGX machine, which only releases the info/bribes if enough shares are collected?

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**Author:** ![guy](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.scrt.network/guy/32/56_2.png) [@guy](https://forum.scrt.network/u/guy)\
**Post date:** [November 14, 2018, 1:11pm UTC](https://forum.scrt.network/t/question-about-the-fundamental-security-of-mpc/453/2 "2018-11-14T13:11:53Z")

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I don’t see this as a new attack vector, it’s just one way to obfuscate collusion - but assuming some amount of honest participants (even as low as 1 node) is part of the threat model with MPC.

In practice, there are several ways to make collusion impractical:

1. Nodes run their MPC computations inside of an enclave - making leakage of shares hard (think about it as compounding the security of both together). I believe that in time, with TEEs becoming more robust, this would become extremely infeasible and more expensive than it’s worth.

2. With a very large network and the committees approach (assuming each committee is large enough), it would be very hard to coordinate a collusion. Even if there are services that make it easy.

3. For really sensitive applications, we should allow for user-centric computations, where users can ensure they hold at least one share of the information.

There are other arguments as well, for example, I believe that the overall utility of playing honest is higher, compared to trying to actively hurt the system in something that would yield short-term higher gains (but potentially no gains in the future - if the system as a whole fails).

Overall, I think such attacks would be more expensive than the utility they’d provide, which would break their viability.