Gold collapsing. Bitcoin UP.

[JorgeStolfi]

For a thing to be a sidechain I guess it would need to first be a chain. Can you point me to Bitstamp's blockchain?

That seems to be an assumption some people make, but I did not see that stated in the paper.  To be meaningful, that statement would require a defintion of what is a "blockchain" and what is not.  Without such definition, I can give several "stupid answers" to that question:

* The sofa in Bitstamp's lounge is "Bitstamp's blockchain".

* Bitstamp's internal ledger, where the accounts are kept, is "Bitstamp's blockchain".

* Bitstamp can create some junk altcoin, say a bitcoin clone, that can be traded on their site; set up an old laptop to start mining its blockchain; and call that "Bitstamp's blockchain".

And also an answer that may not be so stupid:

* Bitstamp could implement @GMaxwell's scheme for "proof of solvency", using a Merkle tree (not linear, but bushy) of the account balances, updated once a day, secured by strategically inserting some hashes in the bitcoin chain; and call that tree "Bitstamp's blockchain".

The last example may show that trying to restrict what a sidechain can be and do is pointless (because there is no practical way to enforce those restrictions) and stupid (because it would arbitrarily exclude many interesting systems, perhaps even the feared "bitcoin killer")

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[cypherdoc]

The 2 papers that come to mind are Sirer's Selfish Mining paper and the Red Balloon paper from Microsoft. I've listened to Sirer talk before which is even more puzzling that he can be so pedantic about it. For Christ's sake, if you're going to stake your academic reputation on such a  theory, at least attack the network to prove it or release the code to meet everyone inspect it for flaws in reasoning or assumptions. He won't do either which should show you what the quality of his thesis is.

Well, Ph. D. theses are often like that.   Speaking as an advisor, after I have stolen five of the best years of someone's life, it would be a crime to send him/her away with empty hands.

Seriously, I did not quite understand how Sirer's Selfish Mining attack works either, but I did not spend much time trying to.
Anyway, even if it works, it does not seem to be fatal, but only make life less fair for miners.  Or is it claimed to be worse than that?

I haven't seen the other paper you mention.

is Sirer the advisor or a co-grad student with co-publisher Eyal?

To me though, as through the 5 other bubbles we've had, is the protocol still hasn't been hacked, tx's are going up, time has advanced (6yrs), dev is getting done, user adoption is growing worldwide, VC's investment continues to accelerate, and huge companies like Microsoft are coming on board.

Well, I am not so optimistic about those things:

* By my understanding of the past bubbles, a new large bubble would require a new large market, comparable to that of the Chinese speculators who adopted Bitcoin in Nov/2013.

that's possible.  but Bitcoin advances in waves.  we are ebbing right now awaiting the next tidal wave.  probably flight from some currency somewhere.

* The cryptographic security of the basic protocol, properly implemented, is assured as long as the basic tools are.  However, people can easily make mistakes when using or even implementing it.  See the recent BCI fiasco, for example.  Claiming that those problems are not bugs "in the protocol" is a weak argument; for prospective users, what matters is the system's security, not the security of the central part.  It is not reassuring to know that Chernobyl, TMI, and Fukushima were not caused by flaws in the physics of nuclear fusion, but to errors in its use.

what part of the current financial system has been trouble free for the last 100 yrs?  no part.  i wouldn't make that huge a deal of the R value problem of BCI.  most of those coins got returned as well so there haven't been great losses.

* The blockchain traffic has been falling recently: tx/day down 18% last week, BTC/day down 44% last month, USD/day down 55%.

that's a short term occurence

* VC investment is almost all in ventures that will make money no matter what happens to the price.  Most merchants who "accept bitcoin", including the large ones, do not want to touch it, they want dollars.  When asked about its future plans for bitcoin, Microsoft dodged the question.  The few minimally reliable data on bitcoin usage for e-payment through BitPay show stagnation in BTC amount over 2014, drop in USD amount.

all those examples are too negative imo.  it's not simply a matter of wanting dollars.  many are holding back some BTC and Bitpay did confirm that.
http://www.reddit.com/r/Bitcoin/comments/2oypbo/bitpay_employee_here_around_50_of_our_merchants/

MS just accepted BTC even after their Red Ballon paper back in 2012.  i guarantee you they aren't going to tell you or i what their long range plans are but this is a turnaround:
http://research.microsoft.com/apps/pubs/?id=156072

[Odalv]

For a thing to be a sidechain I guess it would need to first be a chain. Can you point me to Bitstamp's blockchain?

That seems to be an assumption some people make, but I did not see that stated in the paper.  To be meaningful, that statement would require a defintion of what is a "blockchain" and what is not.  Without such definition, I can give several "stupid answers" to that question:

* The sofa in Bitstamp's lounge is "Bitstamp's blockchain".

* Bitstamp's internal ledger, where the accounts are kept, is "Bitstamp's blockchain".

* Bitstamp can create some junk altcoin, say a bitcoin clone, that can be traded on their site; set up an old laptop to start mining its blockchain; and call that "Bitstamp's blockchain".

And also an answer that may not be so stupid:

* Bitstamp could implement @GMaxwell's scheme for "proof of solvency", using a Merkle tree (not linear, but bushy) of the account balances, updated once a day, secured by strategically inserting some hashes in the bitcoin chain; and call that tree "Bitstamp's blockchain".

The last example may show that trying to restrict what a sidechain can be and do is pointless (because there is no practical way to enforce those restrictions) and stupid (because it would arbitrarily exclude many interesting systems, perhaps even the feared "bitcoin killer")

I think, you are right.

[NewLiberty]

who knows how much further MC achievements might have been accomplished if BS core devs were spending all that time working on Bitcoin Core that they undoubtedly have been dedicating to the spvp for the last year and a half.  forget that shit and get behind Gavin and increase blocksize.  now is the time to do this.

A hard fork to increase blocksize may be needed, but the proposed exponential blocksize growth is both unnecessary and harmful to propagation of the sufficient bitcoin nodes desired for resilience.  

I'm curious to know what you (and others btw) make of Mircea Popescu and his crew's position that blocksize should not (arguably never) be increased

I've published on this matter extensively already.  Block size stagnation to preserve TOR is not sufficient reason.  (Block size is the decompressed size, network layer issues can be resolved at network layers rather than at application layer.)  I also disagree with Mircea P that Block size should be limited as an incentive to increase tx fees in order to support miners.  Miners need no such support.  We have more mining and fewer nodes than we need.

Gavin's proposal is naive wrt security, and prejudiced against increasing nodes (something the network does need), it is likely to decrease them instead.  The notion that market forces rule all and that block size will be constrained by the incremental risk of orphaning a block vis a vis the prospect of a competitive advantage from economies of scale knocking out smaller opposition is short sighted.  It creates a perverse incentive to increase block sizes and stuff them with junk to kill off smaller competitors.  
There are other technical solutions in play which may mitigate this with storage advancements and databasing and UTXO search but with the current state of things, his proposal breaks more than it fixes.  

[cypherdoc]

For a thing to be a sidechain I guess it would need to first be a chain. Can you point me to Bitstamp's blockchain?

That seems to be an assumption some people make, but I did not see that stated in the paper.  To be meaningful, that statement would require a defintion of what is a "blockchain" and what is not.  Without such definition, I can give several "stupid answers" to that question:

* The sofa in Bitstamp's lounge is "Bitstamp's blockchain".

* Bitstamp's internal ledger, where the accounts are kept, is "Bitstamp's blockchain".

* Bitstamp can create some junk altcoin, say a bitcoin clone, that can be traded on their site; set up an old laptop to start mining its blockchain; and call that "Bitstamp's blockchain".

And also an answer that may not be so stupid:

* Bitstamp could implement @GMaxwell's scheme for "proof of solvency", using a Merkle tree (not linear, but bushy) of the account balances, updated once a day, secured by strategically inserting some hashes in the bitcoin chain; and call that tree "Bitstamp's blockchain".

The last example may show that trying to restrict what a sidechain can be and do is pointless (because there is no practical way to enforce those restrictions) and stupid (because it would arbitrarily exclude many interesting systems, perhaps even the feared "bitcoin killer")

Jorge brings up an interesting point. 

Odalv, perhaps you can comment on whether all these federated server SC's that are in action already involve a true blockchain that are MM'd?  i doubt it.  they're probably just internal ledgers.  that doesn't sound like a true SC to me.

[JorgeStolfi]

hmm, I wonder if there are any of those left *scratches head*

If the COIN ETF is approved, perhaps it will open a large market of private investors in the US (savings and retirement accounts, etc.) 

Latin America could be such a market, but there does not seem to be a population of commodities speculators like the Chinese one.  Africa has the same problem, and is much poorer than China.  India seems to be wary of bitcoin (perhaps by memories of Mavrodi's scams).

[sickpig]

It's not that I'm feeding anybody but for everyone interested in keeping this thread signal/noise ratio as high as possible, I've taken the liberty to quote the excellent Peter R's categorization of a particular kind of user:

A Taxonomy of the Troll

Class C bitcoin troll (lat. trollus minimus):

-How to recognize: Simple-minded FUD spreading, and juvenile insults.  

-Recommended response: ignore, their trolling is obvious to everyone and occasionally humorous.  

-Examples: falllllling, Chuckee, fonzie (in the earlier part of his career)

Class B bitcoin troll (lat.  trollus averagus)

-How to recognize: bait-and-switch thread titles and well-executed concern trolling; methods designed to fool the reader into thinking the troll is a non-troll.  

-Recommended response: agree with everything they say in a satirical way.  Their arguments are usually so flawed that simply rephrasing back what they said will reveal their lunacy.  This technique is especially effective if the troll doesn't recognize this attack vector until he's already sunken his ship.

-Examples: Nagle, JorgeStolfi, Edward50

Class A bitcoin troll (lat. trollus maximus)

-How to recognize: usually hold an esteemed position or a PhD.  

-Recommended response: Engage in logical and polite debate.  These are the most difficult trolls to defeat, so you must be patient.  The truth will prevail.  

-Examples: Mark Williams, Paul Krugman, Richard Murphy

[adam3us]

The spv verify opcode looks to me like to me to be in the class of a generically useful inclusions which anyone is free to use for a variety of developments or optimizations of existing developments.

Right.

Do you suppose that anyone involved with Bitcoin dev had any ideas or involvement in efforts which could have made use pay-to-script-hash when it was integrated?  I don't remember you pitching a bitch about that.

Well its interesting you should say that - there were discussions that the script language could have been extended during the p2sh discussion at the time.  eg there was no reason the script inside p2sh couldnt have been a different script language.  Lets say that script had been done, then sidechains might've been possible without a separate change.

Also as I mentioned a few times its already very close to possible to implement a compact SPV verify in bitcoin script.  Anyone of dozens of minor changes to slightly improve expressiveness of bitcoin script would allow it.  It seems close to inevitable that sooner or later an expressiveness or refactor or clean up of bitcoin script will happen, for its own sake and reason: to make it easier or safer to write smart-contracts etc.

About cypherdoc particularly he said this:

I am not sure if you are aware sidechains are nearly possible with zero changes to bitcoin.  Its already programable via the script language.  It may even be doable with zero changes with some chained contorted big script to validate compact SPV proofs.

great, then do it if it doesn't involve a source code change.  i have no problem with that.

So that seems a little inconsistent to me.  ie if this is really a bad idea why would cypherdoc not have a problem with it regardless of whether it required changes or not.  I mean if its a principle you'd be arguing to please not do it even though its possible.  Or to remove something from the language to prevent it, or put a technical defense preventing it if such a thing existed (seems unlikely but I havent explored it much).  Not saying "I have no problem with that."

fundamentally, none of the technical enhancements to Bitcoins money function couldn't be done on the MC.  not easy to gain consensus but it CAN be done.  i'm all for that.  this is what we have testnet and federated server SC's for.  experimentation.  esp when we're only at the $4B market cap.

While its possible, its very much harder, and when changes are made its very much riskier and less secure.  If you care about the security of your coins you should be for having a firewalled live beta and firewalled extension mechanism (if you support improvements "i'm all for that." you said).

it also looks like CP and colored coins will bring us other assets to MC.  that's good too.

CP = CounterParty.  That doesnt bring anything to the chain, other than bloat, its a layered consensus system with its own alt-coin.  If you valued the price of bitcoin, probably you'd be better pushing for sidechains than CP because its bitcoin denominated and increases demand and features for bitcoin.

(Not sure whats up with bitcoin price - maybe its time for reverse psychology: big negative news, generates lots of free press, and there's no such thing as bad press?)

who knows how much further MC achievements might have been accomplished if BS core devs were spending all that time working on Bitcoin Core that they undoubtedly have been dedicating to the spvp for the last year and a half.  forget that shit and get behind Gavin and increase blocksize.  now is the time to do this.

No they spent more time on core than before, because they quit their full time jobs/occupation and Mark said somewhere else on reddit he figured they'd spent 50% of their time at blockstream on core.  (Unrelated to sidechains most of it .. eg in Pieter's case the headers-first speed up you were mentioning, though he's been working on that for a long time).  You could check by looking at bitcoin github, there's a stats page.

fundamentally, i think allowing an offramp for BTC units over to insecure SC's is economically and technically flawed for all the Sound Money reasons i've already articulated.

I fail to see the connection between sound money and an ability to freeze coins with an spv-multisig instead of a multisig.
Bitcoin is protected with a firewall from features on the sidechain.  The bitcoins never leave the chain, they're just frozen in an spv-multisig instead of a multisig.  Lots of people are using multisigs, daily, to effectively do the same thing, its more secure to do it with an spv-multisig.  Lots of people are not even doing that, they're using pure offchain in a shared wallet, for reasons that in time could be fixed on sidechains and then with a year of live testing with $1b on it kind of assurance, ported back into bitcoin main.

improve the MC; it's not that hard.

Yes, it is that hard.  Maybe I dont know do you follow bitcoin-dev, look at github, follow wizards and dev irc?  Making changes to a $4b system is very risky.  op-spv can avoid and reduce that risk, once it is done.

Adam

[Odalv]

For a thing to be a sidechain I guess it would need to first be a chain. Can you point me to Bitstamp's blockchain?

That seems to be an assumption some people make, but I did not see that stated in the paper.  To be meaningful, that statement would require a defintion of what is a "blockchain" and what is not.  Without such definition, I can give several "stupid answers" to that question:

* The sofa in Bitstamp's lounge is "Bitstamp's blockchain".

* Bitstamp's internal ledger, where the accounts are kept, is "Bitstamp's blockchain".

* Bitstamp can create some junk altcoin, say a bitcoin clone, that can be traded on their site; set up an old laptop to start mining its blockchain; and call that "Bitstamp's blockchain".

And also an answer that may not be so stupid:

* Bitstamp could implement @GMaxwell's scheme for "proof of solvency", using a Merkle tree (not linear, but bushy) of the account balances, updated once a day, secured by strategically inserting some hashes in the bitcoin chain; and call that tree "Bitstamp's blockchain".

The last example may show that trying to restrict what a sidechain can be and do is pointless (because there is no practical way to enforce those restrictions) and stupid (because it would arbitrarily exclude many interesting systems, perhaps even the feared "bitcoin killer")

Jorge brings up an interesting point. 

Odalv, perhaps you can comment on whether all these federated server SC's that are in action already involve a true blockchain that are MM'd?  i doubt it.  they're probably just internal ledgers.  that doesn't sound like a true SC to me.

I think we can create blockchain (sidechain) from any data.

There are 2 orthogonal things.
 1) create chain (it can be done by single server .. e.g. Bitstamp trade engine => no MM, no federated server )
 2) verify chain and unlock bitcoins (this can be done by bitcoin network)

[mindrust]

Gold is a currency since the humanity existed.

Gold can't be equal to a 4-year-old-pumpanddump scam.

Btc is failing badly btw.

[smooth]

hmm, I wonder if there are any of those left *scratches head*

If the COIN ETF is approved, perhaps it will open a large market of private investors in the US (savings and retirement accounts, etc.) 

Latin America could be such a market, but there does not seem to be a population of commodities speculators like the Chinese one.  Africa has the same problem, and is much poorer than China.  India seems to be wary of bitcoin (perhaps by memories of Mavrodi's scams).

China may come back.

[smooth]

i have a question for the computer scientists in the crowd. 

i've noticed some things about the WP's over the last coupla years, including Satoshi's, that i wasn't aware of. first, there doesn't seem to be any peer review.  not only that but what strikes me is that it seems that authors come up with a particular logic pattern that makes sense to them and then construct maths to support that logic.  i often don't even see large data sets, testing, or simulations performed.  that supposedly is a standard for proof of a theory.  is this correct?  this is not a criticism of the CS field but just an inquiry to help me understand your field.

in many fields, a hypothesis is asked, then an experiment with blinded investigators along with large #'s of subjects and controls is carried out over a statistically significant time period to rule out investigator bias (can never do that completely) and prove that the hypothesis is correct within a std dev often of p<0.05 or 5%.  i realize these are different methods in different fields so it's hard to determine which is more rigorous.

These sorts of crypto "white papers" are not really academic papers at all. They are marketing for a piece of software (perhaps still under development). They vary in presentation from somewhat academic to not academic at all, but at their core they are entirely different in goals and methodology as you explain

http://en.wikipedia.org/wiki/White_paper#In_business-to-business_.28B2B.29_marketing

[adam3us]

Adam the reason Bitcoin is considered successful thus far is real people have invested in giving it value, running SVP proof on the Bitcoin blockchain just put it all at risk.

Its not clear why you think adding an spv-multisig is worse than multisig or IOUs with offchain holdings (as most exchanges are doing).  That seems reversed to me.  What does it put at risk?

Adam

[adam3us]

SCs have the potential of giving people a false hope of it being equivalent to Bitcoin but in fact not having all of the elements of MC Bitcoin.

True someone could make a hostile sidechain.  But so can people make hostile multisigs (eg freeze your coins and extort you a % of them to get them back), obviously IOU offchain we've seen no-end of offchain things be scams, thefts, or incompetence failures.  Or they could make defective wallets (thats happened a number of times also).

The solution as with everything else with bitcoin is understand what you're doing and/or use software that is signed, on machines without malware, and from people who are competent.  If you cant tell ask someone more competent (not you, but the general novice user).  I wrote about that here:

its caveat emptor, you shouldnt put money into a chain unless there is some assurance that security & bitcoin protocol knowledgeable people have audited it.  People could certify chains (like sign them - "my name is blah and I'm a security researcher with reputation and I and my buddies audited this code and its good") or wallets could etc.  Its good and a feature that people can opt to use uncertified chains.  You want a situation where there is real open possibility for technical innovation & competition in chain features.

You also want no central control so no chains can get black listed.

Adam

[chaoman]

Gold is a currency since the humanity existed.

Gold can't be equal to a 4-year-old-pumpanddump scam.

Btc is failing badly btw.

Since primitive people were using gold as currency we should too? Technology develops and we the people need to change along with it or get left behind. BTC is the future, if you dont have that inkling in your mind then why are you here?

[smooth]

Not sure whats up with bitcoin price

Most likely I think it is just the continued unwinding of China speculation, which took things beyond where system maturity and adoption could really support.

However, if you look at the most recent leg down, it coincides fairly well with the Blockstream announcements. It is possible that the market is responding poorly to this whole business, maybe not side chains themselves as CD suggests, but the idea of several of the top developers being aggregated under a single for-profit umbrella. It just is not good (in terms of perceptions if nothing else) for the role of the system as a neutral open source platform.

Yes it is good that developers have commercial support to work on the core, but neutrality would be served better by the developers getting their support from a more widely dispersed set of interests.

[mindrust]

Gold is a currency since the humanity existed.

Gold can't be equal to a 4-year-old-pumpanddump scam.

Btc is failing badly btw.

Since primitive people were using gold as currency we should too? Technology develops and we the people need to change along with it or get left behind. BTC is the future, if you dont have that inkling in your mind then why are you here?

I am not saying btc is bad. Just dont compare it to gold... It doesn't make any sense. Btc has so many flaws and until those big flaws get fixed, gold simply wins.

[cbeast]

Yes it is good that developers have commercial support to work on the core, but neutrality would be served better by the developers getting their support from a more widely dispersed set of interests.

Don't leave us hanging in the wind like that. What types of interests do you have in mind?

[cypherdoc]

About cypherdoc particularly he said this:

I am not sure if you are aware sidechains are nearly possible with zero changes to bitcoin.  Its already programable via the script language.  It may even be doable with zero changes with some chained contorted big script to validate compact SPV proofs.

great, then do it if it doesn't involve a source code change.  i have no problem with that.

So that seems a little inconsistent to me.  ie if this is really a bad idea why would cypherdoc not have a problem with it regardless of whether it required changes or not.  I mean if its a principle you'd be arguing to please not do it even though its possible.  Or to remove something from the language to prevent it, or put a technical defense preventing it if such a thing existed (seems unlikely but I havent explored it much).  Not saying "I have no problem with that."

if you can implement spvp based SC's w/o a source code change, then i can't stop that.  i might not like it or agree with the principle but that's where the "I have no problem with that" comes from.  tho from everyone's understanding and the WP, you need the spvp obtained via a source code change.  what's important to protect, for me, is the mining and investment assumptions that are based on the current code as it stands. if what you say is true about you being able to implement SC's w/o any source code changes, presumably the market has already factored that into the price and i wasn't aware of that and can't argue with that.  but if you do have to change source code specifically to accomplish what you want, then i do know for sure the market will have to adjust to that new information.  the effects of that will be unpredictable in my mind and upset certainly my assumption of how the source code was never supposed to change to allow a for-profit company to benefit.  i know you say it's generic but you do have a head start in this area along with 5 devs and should establish a monopoly quickly by my estimation.  that is, if the idea and concept works.  which as you already know, i have my doubts.  

fundamentally, none of the technical enhancements to Bitcoins money function couldn't be done on the MC.  not easy to gain consensus but it CAN be done.  i'm all for that.  this is what we have testnet and federated server SC's for.  experimentation.  esp when we're only at the $4B market cap.

While its possible, its very much harder, and when changes are made its very much riskier and less secure.  If you care about the security of your coins you should be for having a firewalled live beta and firewalled extension mechanism (if you support improvements "i'm all for that." you said).

it's not the improvements proposed for SC's that i worry about.  it's about speculators like Truthcoin who not only proposes all sorts of assets but also a altcoin (TC) which will ride on the SC.  

it also looks like CP and colored coins will bring us other assets to MC.  that's good too.

CP = CounterParty.  That doesnt bring anything to the chain, other than bloat, its a layered consensus system with its own alt-coin.  If you valued the price of bitcoin, probably you'd be better pushing for sidechains than CP because its bitcoin denominated and increases demand and features for bitcoin.

as i understand CP, it's just an embedded hash into a 40 byte op_return that originally was 80 bytes.  they were able to compensate so how is that a problem?

who knows how much further MC achievements might have been accomplished if BS core devs were spending all that time working on Bitcoin Core that they undoubtedly have been dedicating to the spvp for the last year and a half.  forget that shit and get behind Gavin and increase blocksize.  now is the time to do this.

No they spent more time on core than before, because they quit their full time jobs/occupation and Mark said somewhere else on reddit he figured they'd spent 50% of their time at blockstream on core.  (Unrelated to sidechains most of it .. eg in Pieter's case the headers-first speed up you were mentioning, though he's been working on that for a long time).  You could check by looking at bitcoin github, there's a stats page.

hmmm

fundamentally, i think allowing an offramp for BTC units over to insecure SC's is economically and technically flawed for all the Sound Money reasons i've already articulated.

I fail to see the connection between sound money and an ability to freeze coins with an spv-multisig instead of a multisig.
Bitcoin is protected with a firewall from features on the sidechain.  The bitcoins never leave the chain, they're just frozen in an spv-multisig instead of a multisig.  Lots of people are using multisigs, daily, to effectively do the same thing, its more secure to do it with an spv-multisig.  Lots of people are not even doing that, they're using pure offchain in a shared wallet, for reasons that in time could be fixed on sidechains and then with a year of live testing with $1b on it kind of assurance, ported back into bitcoin main.

i know you've been saying they're equivalent for a while now but i see a difference.  multisig is currently used just for security purposes as in 2of3.  when necessary, the funds at those addresses can be mobilized immediately, no 2 day delay.  the p2sh used to facilitate these multisigs are not meant to reanimate scBTC on the other side of a 2wp as in your proposal.  with your 2wp (spvp), there is an entire "industry" awaiting on the other side of the 2wp that you wish to capitalize on.  i don't like the concept you used earlier of the BTC still being on the MC.  i see the 2wp as a "pass through" that reanimates those BTC into scBTC on a SC which then facilitates all sorts of speculation and trading of assets or even scCOINS like TC.  the SC's can be anything at all as you've described it and it's BS business plan to sell these newly designed and constructed SC's to willing buyers and maybe even gvt's as you've said.  i think that is risky.

and then there's the whole mining thing.  i'm not sure if you addressed some of my concerns above regarding attacks.

[NewLiberty]

However, there are no details in the paper to even tell what applications could be "sidechains", how the integration would work, what concrete benefits they would derive from that, why other projects could not obtain the same benefits without being "sidechains of bitcoin" -- and why would bitcoin be saved as a result.  Needless to say, there is also no analysis of possible failure modes.

So I take it you didn't read the paper  

I did read it, and also the "sidechains for dummies" blogpost that people recommended, and some more posts.

So what you are saying is that I did not understand it at all.  Perhaps.  But then I ask, for example, why Bitstamp is not already a "sidechain".  OK, it is not decentralized nor merge-mined, but does the whitepaper say that a sidechain must be those things?

My impression is that the paper did not want to rule out anything, for fear that it might prevent co-opting a possible "bitcoin killer".

For a thing to be a sidechain I guess it would need to first be a chain. Can you point me to Bitstamp's blockchain?

They have a ledger but it isn't a block chain.