[HN Gopher] Mojo-V: Secret Computation for RISC-V
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       Mojo-V: Secret Computation for RISC-V
        
       Author : fork-bomber
       Score  : 60 points
       Date   : 2025-11-12 11:57 UTC (7 days ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | pjmlp wrote:
       | And the relationship to Mojo programming language is?
        
       | shakna wrote:
       | This could be:
       | 
       | Great for security - Being able to safely compute secrets is a
       | very difficult problem.
       | 
       | Fucking awful for security - More OEM secret controls and
       | "analytics" that devolve into backdoors after someone yet again
       | post keys online.
        
         | Manfred wrote:
         | The platform owner can manage keys and data contracts in the
         | processor, that should enable them to rotate secrets
         | constantly.
         | 
         | In other hardware there is an OEM secret because the
         | manufacturer is trying to keep users out of "their hardware",
         | in this case we're trying to keep everyone except the data
         | owner out.
        
       | snvzz wrote:
       | RISC-V is inevitable.
        
       | LarsDu88 wrote:
       | Was it really wise to name this Mojo when Chris Lattner, former
       | Head 9f Engineering at SiFive also called his well funded
       | programming language Mojo?
        
         | left-struck wrote:
         | It's called Mojo-V not just Mojo
        
           | craftkiller wrote:
           | So close to Mojave, I feel like they could have done
           | something with that.
        
         | NooneAtAll3 wrote:
         | was it really wise to name both Mojo when Mr.Evil stole it from
         | Austin Powers back in 1999?
        
           | hyperhello wrote:
           | Doctor Evil. He didn't spend six years in evil medical school
           | to be called Mister, thank you very much.
        
       | Manfred wrote:
       | After skimming through the documentation this seems like a nice
       | solution, but I'm not sure if this is a problem we want to solve.
       | 
       | Consumers are finding out the issue with cloud computing when
       | their heating system can't turn on because Cloudflare is down. A
       | cheaper and more reliable solution is still on-premises
       | computing.
       | 
       | Large social network and content platforms don't have any
       | incentive to keep your data safe because they want to monitor and
       | own everything.
       | 
       | Maybe this is for something like a government running a public
       | service?
        
         | throawayonthe wrote:
         | i want good confidential compute for cases where e2ee is
         | impractical, like an email server or immich with server-side
         | ml/processing etc
        
           | Manfred wrote:
           | Who are you protecting data access from in those cases? My
           | suggestion was that it's probably more practical to run those
           | kinds of solutions on a hardware stack you trust; in our
           | basement or in a small box on the wall in your living room.
           | 
           | Besides, the specific extension we're talking about protect
           | registers and computation and not shared memory.
        
             | tonetegeatinst wrote:
             | Issue is, unless you can be 100% sure you hardware has not
             | been built with a vulnerability or backdoor, or subject to
             | an evil maid attack....then you can't be sure its
             | trustworthy.
        
         | nl wrote:
         | > I'm not sure if this is a problem we want to solve
         | 
         | Who is this _we_ you speak of?
         | 
         | I for one much prefer my cloud services and would love TEE I
         | can control.
         | 
         | > A cheaper and more reliable solution is still on-premises
         | computing.
         | 
         | I assure you that my use of Cloudflare services ($0 in nearly
         | 10 years) is much more reliable and much cheaper than hardware
         | I run.
        
           | Manfred wrote:
           | I was genuinely asking, what cloud service do you use where
           | trusted computing is essential for the core functionality of
           | that service? What elements of the computational process do
           | you not trust those services to perform for you?
           | 
           | My point about Cloudflare was more about them taking down
           | essential services that could run just as well on-premises
           | like a heating controller.
        
       | tromp wrote:
       | This should not (so much) be compared with Fully Homomorphic
       | Encryption (FHE) but with a Trusted Execution Environment (TEE).
       | It is a very elegant and minimal way to implement TEEs, but
       | suffers from the same drawbacks: a data owner has to trust the
       | service provider to publish the public keys of actual properly
       | constructed Mojo-V hardware rather than arbitrary public keys or
       | public keys of maliciously constructed Mojo-V hardware.
       | 
       | [1] https://en.wikipedia.org/wiki/Trusted_execution_environment
        
         | api wrote:
         | You could have the keys signed by a chip maker, which cuts the
         | hosting provider out and reduces the trust surface to the
         | manufacturer only. Unless your adversary is someone
         | sophisticated enough to do surgery on chips.
         | 
         | It's still not FHE but it's about as good as you can get
         | otherwise.
        
           | childintime wrote:
           | Couldn't the keys be loaded once, in private write-only flash
           | memory, by the user of the chip?
        
             | tromp wrote:
             | The intended use case is for remote execution where the
             | user (data owner) pays a service provider to run services
             | on their hardware. It could still work if the user somehow
             | prepares the chip herself and ships it to the service
             | provider to be used on their future data, but most users
             | would not want to bother with that first step.
        
           | goku12 wrote:
           | > Unless your adversary is someone sophisticated enough to do
           | surgery on chips.
           | 
           | Since the threat assessment is important for deciding the
           | strength of countermeasures, let me just add that this isn't
           | as uncommon as you may believe. A company that I worked for
           | had a decent capability to do this, and they were using it
           | just to investigate the failures of electronic subsystems in
           | their projects. Imagine what a more dedicated entity could
           | achieve. This is why standards like FIPS 140-2/3 level-3/4
           | are very relevant in a significant number of corporate cases.
           | 
           | Talking about chip surgeries, I wish our distinguished expert
           | Ken Shirrif could throw some light on the process. His work
           | on legacy chips is one of the most noteworthy in the field.
        
         | technocrat8080 wrote:
         | To be clear, it's not a TEE replacement but does address one of
         | the most common use cases of TEEs
        
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       (page generated 2025-11-19 23:01 UTC)