These were absurdly hard to write and, as often happens when something
is that hard to write, they don't appear to be helpful, as judged by
Murch. The last time I tried to explain the theory[1], it also sucked,
so maybe this isn't what I'm meant to do. :-)
The removed text introduces the term "mempool" for this chapter, so a
small edit is made later on to compensate.
[1] https://en.bitcoin.it/wiki/Miner_fees#The_market_for_block_space
- Drop box with Wikipedia definition of digital signatures. It didn't
add anything and its accuracy was debatable.
- Use "commitment hash" earlier and more often.
- Fix some variable-name errors in the math
- Correct info about worst-case signature verification cost
During his review, Mark "Murch" Erhardt discovered that the appendix
contained several errors and many entries that were confusing. When I
looked at the upstream source on the wiki, I discover that it had extra
information that eliminated those problems. Since we only reference the
appendix twice, don't really go into detail about writing your own
scripts, and since all the information is easily accessible online for
free, we drop the appendix and replace references to it with a link to
the wiki.
- Describe OP_CMS pubkey limits for consensus, relay policy, and P2SH.
- Mention that OP_CLTV and OP_CSV leave elements on the stack, unlike
other VERIFY opcodes.
- Explicitly describe what BIPs are before we start dropping references
to them.
- Mention that addresses don't encode a message, so using a unique
address that the receiver has privately associated with a spender is
the only guaranteed way to identify payments from that spender.
- Correct how many blocks need to elapse before an output can be spent
by an input with a relative lock time.
- Many other small edits.
- Mention the reason for the long validation time is the verification of
transactions. We previously implied it was download time, but some
people have really fast internet.
- Better describe bitcoind cookie authentication and provide an example
to make it even more clear.
- Add a link to bitcoin-s
- Make the long sidebar on collision attacks even longer by descripting
a pre-image attack in addition to the previous descriptions of second
pre-image and collision. That way we don't conflate pre-image and
second pre-image.
- Remove redundant tip box about an oddity in language about compressed
and uncompressed private keys.
- Link to information about vanity address "mining" (brute forcing)
- Fix bitcoin-overview image (P2PKH address was used as "private key")
- Use receiving and sending images from Bitcoin Design Guide
(https://bitcoin.design) under CC-BY license
(https://github.com/BitcoinDesign/Guide/blob/master/LICENSE)
- Mention changeless outputs, especially as used in transaction-chain
image
- Include brief mention of best blockchain in paragraph about the cost
to miners for confirming conflicting transactions
- Drop unnecessary mentions of people from CH01
- FIXMEs: add notes for image corrections and best blockchain change
- Drop unnecessary mention of debits and credits
- Remove mention about asking block explorer for UTXOs to construct a
transaction. This is unnecessary detail and it can never entirely
work for our example if we later use it to spend the output (because
then the output won't be unspent)
- Instead of "new block" use "candidate block"
- Drop unnecessary mention of payment consolidation. We already
adequetely introduce this concept earlier in the chapter.
- Provide rough block and year when 99% of all BTC will have been mined
- Remove user-stories section. I think this section frontloaded too
much irrelevant detail. In new sections of this edition, I've
exclusively used the convential Alice, Bob, Carol, etc.---without
trying to maintain a consistent backstory. This is simpler on the
writer and, I think, simpler on the reader---if they jump into a
section of the book, they don't need to worry that there's some
important context in a previous section.
- This also necessitated a few changes chapter 2.
- Mostly remove the phrase "custody". Instead use the phares "control
the key". I think this is clearer to non-specialists and a quick grep
shows that we don't use any version of the word "custody" elsewhere in
the book.
- Drop localbitcoins.com. This service was terminated after this
chapter was updated.
- Add 'feerate' to the script for catching forbidden words. :-( This
required a change to a comment in an image source.
- Other minor changes and typo fixes
- BIPs: it's silly to repeat all BIPs in the book, especially when an
increasing number have never been used or are just silly. Instead,
use the list of implemented BIPs from the Bitcoin Core project, which
represents a list of mostly interesting BIPs.
- Add OP_CHECKSIGADD from tapscript to the Script copypasta.
- Bitcore removed per outline
- s/bitcoin/Bitcoin/ when appropriate
- Proof of work is only part of security
- Mining is separate from verificatino
- Kill BIP38 encrypted private keys section (mention seeds instead)
Previously, the text went into a lot of detail about block 277,315,
which was a long time ago. We generalize the text to make it
perpetually current (barring a hard fork).
The previous list mixed consensus rules that transaction must follow
with standard transaction policy, which I think was confusng for readers
and also a problem in a later reference where we claim that all
transactions in a block must follow the rules (true for consensus; false
for policy).
This short subsection described segwit's use of always-true
scriptPubKeys as special. It didn't mention the similar mechanism used
for BIP16 P2SH. It also doesn't mention block-focused changes like
BIP32 and BIP34, or non-script changes like BIP66, BIP68, and BIP113.
I think it should either be greatly expanded or removed, and removing is
easier right now. :-)
"Smore" sounds like "Schnorr", which could be confusing. Also, we
have upgraded signatures now without a soft fork, so the example is
confusing. Although we could add another coin with a soft fork (sort
of), it seems a lot less likely to me, so I think it's a better cadidate
for this section.
