editing WIP

1 files changed, 26 insertions, 26 deletions

diff --git a/introduction.tex b/introduction.tex
index abeec66..edadde7 100644
--- a/introduction.tex
+++ b/introduction.tex
@@ -45,7 +45,7 @@ This thesis covers both categories of payment systems:
 GNU Taler is an official package of the GNU
 project\footnote{\url{https://gnu.org/}}, and the BSC protocol was
 implemented in the \textsc{CONSENSUS} subsystem of the GNUnet
-framework\footnote{\url{https://gnunet.org}}. Our Free Software
+framework\footnote{\url{https://gnunet.org}}. Our free software
 implementations are freely available from the GNU mirrors.
 
 
@@ -185,7 +185,7 @@ supports the more highly ranked goal is preferred:
   \item \textbf{GNU Taler must foster competition.}
 
     It must be relatively easy for competitors to join the systems.  While the
-    barriers for this in traditional financial systems are rather high, the the
+    barriers for this in traditional financial systems are rather high, the
     technical burden for new competitors to join must be minimized. Another
     design choice that supports this is to split the whole system into smaller
     components that can be operated, developed and improved upon independently,
@@ -238,7 +238,7 @@ double-spent.  In an offline e-cash system, the detection of such an event is
 greatly delayed compared to systems with online spending, which can immediately
 detect when more coins are spent than were issued.
 
-Thus in GNU Taler, we decided that all coins must be immediately
+Thus, in GNU Taler, we decided that all coins must be immediately
 deposited online during a purchase.  Only either merchant or customer
 need to be online, since one of the two can forward messages to the
 payment service provider for the other.
@@ -265,7 +265,7 @@ wallets and the communication cost of withdrawals.
 The current state of the art for divisible e-cash~\cite{pointcheval2017cut}
 achieves constant-time withdrawal and wallet storage cost for coins that can be
 split into an arbitrary but fixed (as a system parameter) number of pieces.  A
-continuous ``chunk'' of the smallest pieces of coin can be spent with
+continuous ``chunk'' of the smallest pieces of a coin can be spent with
 constant-time communication complexity.
 
 While this sounds attractive in theory, these results are mostly of academic
@@ -337,7 +337,7 @@ of a coin.
 Atomic swaps (often called ``fair exchange'' in the e-cash literature) are a
 feature of some e-cash systems that allows e-cash
 to be exchanged against some service or (digital) product, with a trusted third
-party ensuring that payee receives the payment if and only if they correctly
+party ensuring that the payee receives the payment if and only if they correctly
 provided the merchandise.
 
 GNU Taler supports Camenisch-style atomic swaps~\cite{camenisch2007endorsed},
@@ -541,17 +541,17 @@ aware of any other treatments of income transparency and conservation.
 
 \section{Distributed Ledgers} \label{sec:intro:blockchain}
 
-The main purpose of Blockchains, including those implementing
+The main purpose of blockchains, including those implementing
 cryptocurrencies, is to maintain a distributed ledger that holds
 state, together with rules on how this state can be updated.  The name
-``Blockchain'' derives from its structure: A list of updates
+``blockchain'' derives from its structure: A list of updates
 (``transactions'') is bundled into a so-called block, and each block
 contains a hash of the previous block.  Cryptocurrencies use
-Blockchains to remember the amount of currency controlled by a
+blockchains to remember the amount of currency controlled by a
 particular account ($\equiv$ private key).  Thus, while
 cryptocurrencies use the term ``coin'' (creating potentially misleading associations
 with cash), they actually realize a decentralized register-based
-payment system with the Blockchain storing the register\footnote{%
+payment system with the blockchain storing the register\footnote{%
 Anonymous cryotocurrencies such as ZeroCash \cite{bensasson2014zerocash}
 have special accounts (called shielded addresses) that can
 ``hide'' their balance, and require the owner to prove in zero knowledge that their balance is sufficient for a transaction.
@@ -560,7 +560,7 @@ are closer to value-based systems.  However, currently only a small percentage (
 all funds in ZCash, the most widely used anonymous cryptocurrency, belong to shielded addresses (\url{https://explorer.zcha.in/statistics/value}).} using private
 keys to authenticate account owners.
 
-Cryptocurrencies based on Blockchains gained immense popularity over
+Cryptocurrencies based on blockchains gained immense popularity over
 the last years on the promise of a universal, global and decentralized
 payment system that is independent from country boundaries and
 legislations.  In practice, however, current incarnations of these
@@ -568,7 +568,7 @@ technologies can only handle a handful of transactions, have high
 transaction fees and are surprisingly centralized
 \cite{beikverdi2015trend,bohme2015bitcoin}.  Bitcoin, the most popular
 cryptocurrency, can handle around 3-7 transactions per second,
-globally.  While there are various plans to make Blockchains more
+globally.  While there are various plans to make blockchains more
 scalable~\cite{green2016bolt}, there is no concrete evidence that
 any of them will work without further sacrificing % the existing advantages of
 decentralization.
@@ -576,15 +576,15 @@ decentralization.
 
 \subsection{Consensus in Decentralized Blockchains}
 
-In decentralized Blockchains, multiple parties must agree on the current state of
+In decentralized blockchains, multiple parties must agree on the current state of
 the ledger by agreeing on a ``head'' of the chain of blocks.  How to advance
 this head to include new transactions is thus a critical design choice.
 
-With proof-of-work Blockchains such as Bitcoin, each block contains
+With proof-of-work blockchains such as Bitcoin, each block contains
 the solution to a computationally expensive puzzle that is derived
 from the contents of the block.  The block that, together with its
 ancestors, contains the most expensive accumulated work (and respects
-the rules of the Blockchain with regards to what transactions are
+the rules of the blockchain with regards to what transactions are
 valid) is considered the head of the chain.  All participants of the
 network can ``mine'' a block by collecting transactions and trying to
 solve the corresponding computational puzzle.  Successful miners are
@@ -598,9 +598,9 @@ remains secure as long as an adversary has less than 1/4 of
 computational power \cite{eyal2018majority}---it consumes a huge amount of energy to provide
 for computation of the proof-of-work puzzles.
 
-After Bitcoin popularized the concept of Blockchains, alternative consensus
+After Bitcoin popularized the concept of blockchains, alternative consensus
 mechanisms were proposed to replace or augment proof-of-work.  In
-proof-of-stake Blockchains, a single node is selected as a validator.  The
+proof-of-stake blockchains, a single node is selected as a validator.  The
 validator must provide a safety deposit (the ``stake''), and if any misbehavior
 is detected, the safety deposit is destroyed.  If the validator behaves
 correctly, they earn transaction fees and get back their safety deposit.
@@ -609,16 +609,16 @@ falling back to other consensus mechanisms in certain situations.
 
 \subsection{Permissioned Blockchains}
 
-Permissioned Blockchains have a known, relatively small set of participants,
+Permissioned blockchains have a known, relatively small set of participants,
 and can rely on more traditional and cheaper consensus algorithms.  When
 resilience against actively malicious members is required, a so-called
 Byzantine consensus protocol must be used.  Byzantine consensus protocols
 typically agree on a single value at once.
 
 In Chapter~\ref{chapter:consensus} we introduce a Byzantine consensus
-algorithm that can be used to agree directly on a (super)set of all
+algorithm that can be used to agree directly on a (super-)set of all
 transaction that honest peers proposed.  This allows for
-implementations of permissioned Blockchains where transactions are
+implementations of permissioned blockchains where transactions are
 accumulated into blocks, and the transactions within a block are
 agreed upon in a way that's asymptotically faster than agreeing on
 every transaction sequentially.
@@ -631,10 +631,10 @@ system, with GNU Taler e-cash as the value-based layer above it.
 \subsection{Blockchains and GNU Taler}
 
 Blockchains today fail to satisfy most of our design goals for payment
-systems.  While most Blockchains are implemented as Free Software,
+systems.  While most blockchains are implemented as free software,
 they often manage to both fail to adequately protect the privacy of
 buyers {\em and} to enable the state to crack down on illegal
-activities: With most non-permissioned Blockchains, the transaction
+activities: With most non-permissioned blockchains, the transaction
 history of all participants is publicly available, creating serious
 privacy risks.~\cite{meiklejohn2013fistful,jawaheri2018small} At the same
 time, as accounts are simply private keys, states have a hard time
@@ -642,19 +642,19 @@ tracking down users.~\cite{luu2016challenge} Design
 variations that do offer reasonable privacy generally have even more
 atrocious performance characteristics and create additional
 traceability problems for law enforcement.~\cite{bensasson2014zerocash}
-Additionally, Blockchain-based cryptocurrencies suffer from usability
+Additionally, blockchain-based cryptocurrencies suffer from usability
 and performance problems.
 
 With our BSC protocol, we focus on improving the performance of the
-consensus protocol for permissioned Blockchains.  Permissioned
-Blockchains can be given rules that enforce Know-Your-Customer (KYC)
+consensus protocol for permissioned blockchains.  Permissioned
+blockchains can be given rules that enforce Know-Your-Customer (KYC)
 and Anti-Money-Laundering (AML)
 regulations.~\cite{shrier2016blockchain} When deployed in the
 context of centrally banked fiat currencies, such a permissioned
-Blockchain can then effectively recreate the semantics of a classical
+blockchain can then effectively recreate the semantics of a classical
 distributed banking system.  As mentioned before, GNU Taler's
 value-based protocol can be integrated with any kind of register-based
-banking---including those based on Blockchains---improving
+banking---including those based on blockchains---improving
 performance and privacy for value-based transactions.
 
 % block structure