35th DistSys Reading Group - Nym

In our previous session we looked into Mixnets, more specifically Loopix. With this session we stayed in the space, talking about a network adopting many concepts from Loopix, namely Nym. As a preparation, we read section 1 through 4 of the Nym whitepaper. Introduction Network-level surveillance The Nym Network Design Mixnet for Network-Level Privacy Diaz, Claudia, Harry Halpin, and Aggelos Kiayias. “The Nym Network.” (2021). https://nymtech.net/nym-whitepaper.pdf

June 29, 2021 · Max Inden

34th DistSys Reading Group - Mixnets

34th session was on Mixnets as lots of people suggested in the past. As a preparation we read the Loopix paper. Piotrowska, Ania M., et al. “The loopix anonymity system.” 26th {USENIX} Security Symposium ({USENIX} Security 17). 2017. https://www.usenix.org/system/files/conference/usenixsecurity17/sec17-piotrowska.pdf The corresponding talk by Ania Piotrowska is very much worth watching as an additional resource. https://www.youtube.com/watch?v=R-yEqLX_UvI

May 10, 2021 · Max Inden

33rd DistSys Reading Group - BGP 3

In our third BGP session we focused on BGP security, more specifically we discussed how to perform hijack and interception attacks using BGP. The primary paper of the session was: Birge-Lee, Henry, et al. “Sico: Surgical interception attacks by manipulating bgp communities.” Proceedings of the 2019 ACM SIGSAC Conference on Computer and Communications Security. 2019. A good introduction to RPKI can be found here.

April 12, 2021 · Max Inden

32nd DistSys Reading Group - BGP 2

After our first BGP session, introducing the protocol based on the convergence problem of BGP, our second session on BGP covered route propagation and tuning. The primary paper was: Gray, Caitlin, et al. “BGP Beacons, Network Tomography, and Bayesian Computation to Locate Route Flap Damping.” Proceedings of the ACM Internet Measurement Conference. 2020.

March 18, 2021 · Max Inden

Optimizing Yamux Flow Control - Sending Window Update Frames Early

Below is a summary of our efforts to optimize flow control in the Rust Yamux implementation. While not a novel approach, I still find the end result worth sharing thus my forum post. https://discuss.libp2p.io/t/optimizing-yamux-flow-control-sending-window-update-frames-early/843

March 7, 2021 · Max Inden

31st DistSys Reading Group - BGP 1

We decided to turn our interest to BGP which we will devote 3 sessions to. In today’s session - the first one - we introduced BGP, looked at the convergence problem, as well as the solution suggested in the paper below. Gao, Lixin, and Jennifer Rexford. “Stable Internet routing without global coordination.” IEEE/ACM Transactions on networking 9.6 (2001): 681-692. To play around with BGP as well as general Internet routing:...

February 24, 2021 · Max Inden

30th DistSys Reading Group - NTP

What better way to start a new year than with a paper discussing how to change time? In the 30th session we discussed a paper which I think has much up its sleeves - Attacking the Network Time Protocol. First off the paper gives us a good introduction to the inner working of the network time protocol. Next up it examines the broader ecosystem as well as why we need accurate time in the first place....

January 26, 2021 · Max Inden

28th DistSys Reading Group - Hotstuff

With the 28th session we jumped into the space of byzantine fault tolerant consensus protocols. We covered fault tolerant consensus with various Paxos variants in the past, but this session was the first one looking into how to solve the byzantine generals problem. Instead of using PBFT [1] as a first paper we went with Hotstuff [2] instead. The reasoning behind this choice was (a) Hotstuff presenting a somewhat easy up-to-date consensus algorithm and (b) that it provides a framework enabling one to compare other algorithms (e....

September 8, 2020 · Max Inden

Know your latencies

I find it helpful to know the orders of magnitude by which certain computer operations differ. Certainly it is not worth the effort to pay attention to every digit or learn these by heart, especially since they differ (slightly) across systems, but having a basic understanding of what a tiny fraction of time a CPU cycle occupies compared to sending a TCP packet is incredibly helpful whenever reasoning about systems performance....

June 19, 2020 · Max Inden

26th DistSys Reading Group - Cache coherence

We have long been planning to cover the caching mechanisms in CPUs. As a shared knowledge base for the discussions in this session we chose the following two articles by Martin Thompson among other things known for his work on the LMAX Disruptor: CPU Cache Flushing Fallacy including a good overview over the different caches in modern Intel CPUs. Write Combining exemplifying the advanced mechanisms one can find in today’s CPUs and how one can make use of them....

May 18, 2020 · Max Inden