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lazard

57 karma · joined August 14, 2014

PhD student at MIT
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lazard··on Go 1.12 Released
How can we help with getting support for Ed25519 in crypto/x509 and crypto/tls?
lazard··on Vuvuzela: Metadata-private messaging
Not possible yet, but I have some ideas.
lazard··on Vuvuzela: Metadata-private messaging
Our followup Karaoke system [1] can support more users by adding more servers, but we still have more work to do to support billions of users. Regardless, I think it's worth deploying these research prototypes to get a sense of what problems matter to users.

[1] https://vuvuzela.io/static/karaoke.pdf

lazard··on Vuvuzela: Metadata-private messaging
It doesn't yet. I'd like to integrate Karaoke's techniques into the Vuvuzela client in the coming months.
lazard··on Vuvuzela: Metadata-private messaging
Thanks. I just added our latest paper to the list.
lazard··on Vuvuzela: Metadata-private messaging
Sorry! We signed and uploaded new configs, so it should be working now.
lazard··on Vuvuzela: Metadata-private messaging
Sorry about that. I need some way to prevent someone from quickly registering many email addresses. Do you have any other ideas?
lazard··on Vuvuzela: Metadata-private messaging
Our latest paper, Karaoke, achieves 6.8 seconds with 2 million active users: https://vuvuzela.io/static/karaoke.pdf
lazard··on On Password Managers
Nice! Looks similar to Seal [1] (also written in Go). I just added a link to Pick under related work.

[1] https://github.com/davidlazar/seal

lazard··on Ask HN: What is your password management solution?
I used pwclip [1] for several years but I no longer believe that hash-based password managers are the best plan. Now I'm using Seal [2], which is like pass but doesn't depend on gpg.

[1] https://github.com/davidlazar/pwclip

[2] https://github.com/davidlazar/seal

lazard··on Mid-stack inlining in the Go compiler
We measured 10% improvement on ppc64.
lazard··on Mid-stack inlining in the Go compiler
The compiler got a bit slower:

https://github.com/golang/go/issues/19386

Those numbers are just for my CLs that fix stack traces but with mid-stack inlining still off. Turning it on makes builds noticeably slower:

    $ time ./make.bash
    real: 45.32s  user: 118.67s  cpu: 5.85s

    $ time GO_GCFLAGS='-l=4' ./make.bash
    real: 64.51s  user: 167.04s  cpu: 7.12s
We'll need to tweak the inlining heuristic to find a good balance between performance, build times, and binary size.
lazard··on Mid-stack inlining in the Go compiler
The plan is to add inlining information to the DWARF tables so that debuggers and other tools can take advantage of it.
lazard··on Vuvuzela: private messaging system that protects metadata
Only temporarily. I'm interning on the Go team, but still working on Vuvuzela and Alpenhorn in my spare time.
lazard··on Vuvuzela: private messaging system that protects metadata
Author here.

I've been working on a follow-up system called Alpenhorn that addresses the bootstrapping problem in Vuvuzela: https://vuvuzela.io/alpenhorn-extended.pdf

I will release Alpenhorn and a new version of Vuvuzela in January.

lazard··on Pretty Curved Privacy
I built flycrypt as a highly simplified PGP based on NaCl. I've used it to send credit card numbers and passwords over email.

https://github.com/davidlazar/flycrypt

lazard··on WhatsApp's Signal Protocol integration is now complete
We're using noise to hide metadata in the Vuvuzela messaging system [1]. Using noise to hide metadata is efficient and gives good privacy (better than Tor-based approaches). We've formalized the privacy guarantee using differential privacy and are now working to make the system more user-friendly and easier to deploy.

[1] https://github.com/davidlazar/vuvuzela

lazard··on Vuvuzela – Private messaging system that hides metadata
The slides toward the end of my talk [1] try to give some intuition for Vuvuzela's security in terms of "jury certainty".

[1] https://davidlazar.org/slides/vuvuzela-sosp2015.pdf

lazard··on Vuvuzela – Private messaging system that hides metadata
Author here:

The latency can be reduced by future work. For example, Section 9 in the paper mentions an idea for reducing the amount of noise (and thus reducing latency) by treating honest users as noise.

Vuvuzela can also be configured with a smaller "privacy budget" to reduce latency.

lazard··on Ask HN: What bookmarking service do you use?
I created my own: https://github.com/davidlazar/jotmuch