change format to disc

pdf/grandpa.tex

@@ -56,7 +56,7 @@ The underlying problem which enables these attacks is that first generation bloc
 New generation protocols~\cite{kokoris16enhancing,decker16bitcoin,pass16hybrid} propose the complete opposite, to forfeit liveness when finality is not readily achievable.
 This can  only happen if we  change the existing infrastructure and has multiple additional shortcomings.
 First, these ``hybrid'' consensus protocols are exclusive. The protocol needs to put a limit on the number of participating miners in order to achieve good performance, which might lead to centralization. 
-Second, tying consensus with liveness of the chain means that there is no optimism and blocks are committed only when all verification information are available.\xxx{Al:Describe why this is a problem in the context of polkadot and other probabilistic protocols.}
+Second, tying consensus with liveness of the chain means that there is no optimism and blocks are committed only when all verification information are available. As a result, they lose the ability to make some (unsafe) progress when the network is unstable, which can help speedup the recovery process when the network heals. \xxx{Al:Describe why this is a problem in the context of polkadot and other probabilistic protocols.}
 
 
 In this work we show the  that the middle ground also merits exploration. We introduce the idea of lazy finality which is encapsulated in the abstraction of a \emph{finality gadget.}
@@ -70,8 +70,8 @@ More specifically, this work introduces the abstraction of a \emph{finality gadg
 provides provable finality guarantees instead of probabilistic.
 To this end we formalise the finality gadget problem and show that it is impossible to satisfy its properties with a deterministic asynchronous protocol. 
 To circumvent this impossibility result , we introduce the GRANDPA finality gadget that works in a partially synchronous network model, in the presence of up to $1/3$ Byzantine actors. 
-The combination of GRANDPA with a classic block production mechanism like GHOST~\cite{lewenberg15inclusive} results in the existing deployment of the polkadot network which provides fast finality under good network conditions and protects the clients without compromising the liveness when under attack.
-In our evaluation \xxx{add results}
+The combination of GRANDPA with a classic block production mechanism like GHOST~\cite{lewenberg15inclusive} results in the existing deployment of the polkadot network which provides fast finality under good network conditions and protects the clients without compromising the liveness when under attack. The implementation of GRANDPA will be made available on github.
+
 
 In summary we make the following contributions:
 \begin{itemize}
@@ -80,13 +80,9 @@ In summary we make the following contributions:
 
 \item Prove that BFG is impossible in asychrony and present GRANDPA
 
-\item Implement GRANDPA and evaluate it on the large scale network of a major blockchain system
 \end{itemize}
 
 
-The rest of the paper is organized as follows:
-
-
 %The approach that we will take is similar to the approach that Ethereum plans to take with Casper the Friendly Finality Gadget (Casper FFG)\cite{CasperFFG}, which combines these approaches.
 %We will use a block production mechanism and chain selection rule that give eventual consensus and then add a finality gadget, a protocol that finalises blocks that the participants already agree on, to get provable finality.
 
@@ -98,7 +94,7 @@ The rest of the paper is organized as follows:
 
 
 We want to formalise the notion of finality gadget to be a sub-protocol that can be deployed along any protocol with
-eventual consensus and probabilistic finality and enhancing it with provable finality.
+eventual consensus and probabilistic finality and enhancing such protocol with provable finality.
 To achieve this, we need to incorporate into the classic definition of Byzantine agreement 
 the fact that we additionally have access to a protocol that would achieve eventual consensus if we did not affect it.