5

Plausible liveness from arxiv

This is from the Casper FFG document on Arxiv.

  1. Is a higher than b? If so how is b the target checkpoint if it is lower?
  2. If a' is a descendant of a (which I take means a previous checkpoint) how does h(a') = h(b) + 1 look like?
  • Can you also give me the brief example you showed to Meshugah? I have the same question about Plausible liveness. Thanks. – Eric Gong Jun 3 '18 at 1:19
4

Rode this a few weeks ago. Let's try to explain it.

Supermajority links are the way in which the checkpoints are related more efficiently, as you can see on the photo provided, on figure C, supermajority links let us verify the blocks/chain so much faster because let us make "safe assumptions"

  • A is the highest justified checkpoint.
  • Target checkpoint B is the highest on everyone is betting now (more than 2/3 as the protocol requires.
  • Then, if any A'(descendant of the highest justified checkpoint) which is obviously justified because it's a descendant of a justified checkpoint, has a greater height than the target checkpoint B, we can assume, we can go directly to look at A checkpoint. And to don't loose this time evaluating the checkpoint B, is why the supermajority links are implemented.

Support to explanation

EDIT Add the graph where Account safety and Plausible Liveness are demonstrated: Helping graph

The paper's description of the picture and site where apply the example.

description

Here you have the definitions as the paper/Article says: Definitions

Well, hope it helps!

  • Could you give me a very brief example using the diagram. There isn't an 'A' so if you could give me an example with an 'A' and 'B' marked, that would be spectacular. – Vignesh Karthikeyan May 23 '18 at 18:47
  • Done, hope it helps! – CPereez19 May 23 '18 at 19:12
  • hahaha thanks, but i posted this question originally because there was only a diagram for Accountable safety and not Plausible liveness. Does the second diagram provide a correct example? – Vignesh Karthikeyan May 23 '18 at 19:14
  • Yes, the thing is that the Plausible Liveness and Accountable Safety go together. Explained and on the action. – CPereez19 May 23 '18 at 19:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.