Merge branch 'background' of https://github.com/AAU-Dat/P9-ZKP into b…

…ackground

report/src/bib/main.bib

@@ -252,4 +252,20 @@ @misc{heimbach2024deanonymizingethereumvalidatorsp2p
     primaryClass={cs.CR},
     url={https://arxiv.org/abs/2409.04366},
 }
-https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/beacon-chain.md
+https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/beacon-chain.md
+
+@article{random-selection,
+    title        = {Random Selection},
+    author       = {@corwintines and @pettinarip and @nhsz and @nalepae},
+    note         = {Accessed: 21-11-2024},
+    url = {https://ethereum.org/en/developers/docs/consensus-mechanisms/pos/block-proposal/#random-selection}
+}
+
+@inproceedings{upgrading-ethereum-randomness,
+    author = {Edgington, Ben},
+    title = {Randomness},
+    year = {2023},
+    url = {https://eth2book.info/capella/book.pdf},
+    booktitle = {Upgrading Ethereum},
+    pages = {134–149}
+}

report/src/sections/02-background.tex

@@ -140,6 +140,24 @@ \subsubsection{Validator punishments}\label{subsubsec:valpunish}
 At worst, a validator can end up having all their ETH burned, if enough other validators are also slashed.
 
 \subsection{RANDAO}\label{subsec:randao}
+As mentioned in~\autoref{subsec:validator}, the validators are chosen to propose a block by a random-number-generator called RANDAO\footnote{\href{https://github.com/randao/randao}{RANDAO - GitHub}}.
+The random selection is decided by the RANDAO algorithm, which is used every slot.
+Each chosen proposer will get the RANDAO value computed at the previous slot and \texttt{XOR} it with the hash of their private key and epoch number.
+
+
+This creates what is called the RANDAO reveal.
+It can be verified with the proposer's public key.
+This, of course, happens at all 32 slots of an epoch, making up the randomness of the reveal.
+At the end of each epoch, the latest reveal constitutes to the seed, which is used to determine who the next proposers are going to be.
+
+
+Being chosen as a block proposer comes with some duties, such as creating the block.
+This means that they need to know in advance if they are going to be the proposer of a block.
+
+The proposer selection among the validators is done two epochs in advance~\cite{random-selection}.
+More specifically, the selection for epoch $n+2$ happens at the end of epoch $n$~\cite{upgrading-ethereum-randomness}.
+This means that a validator knows at least one epoch, at most two epochs, in advance if they are proposing a block.
+
 
 \subsection{ENR}\label{subsec:enr}
 A~\gls{enr} is a record that contains information about a node in the network~\cite{EIP-778:Ethereum-Node-Records}.