Bitcoin Forum

Are bitcoins indestructible?

Yes they can be lost but are they indestructible?

I think that they are very different to tulip bulbs which can be farmed and can rot away.

So I don't think it is a fair analogy to bitcoins to tulip bulbs as this Dutch banker attempts to:

http://www.theguardian.com/technology/2013/dec/04/bitcoin-bubble-tulip-dutch-banker

One would have to question Nout Wellink's motivation here. Does he really believe bitcoin is unsound money or perhaps does he perceive is that his social status is under threat. Is he slandering bitcoin in a vain attempt to preserve his privileged position in society?

yes

It's impossible to send them to an invalid address, BUT it's entirely possible to send them to an address for which no one has the key.

Take for example: 1BitcoinEaterAddressDontSendf59kuE

Check it out on blockchain. If you can brute force the private key, the coins are yours. Is it impossible? Theoretically, no, but practically...

Let's say you had a super computer that was guessing 999 trillion keys per second. It would take you 3.5 billion years to exhaust just 10% of the keyspace, which means in 3.5 billion years you would have a 10% chance of having guessed the key. Good luck with those odds!

They can be destroyed by mining.

The protocol limits the miners reward to be less than or equal to the amount of the subsidy plus fees.  I am not sure if it was intentional (can't think of a reason) or simply an oversight but this means the reward to miner can be less than the subsidy and fees.

So miner creates a block with tx totaling x BTC in fees and y BTC in subsidy and gives himself 0 BTC coinbase reward.  x + y BTC have been permanently destroyed.

Likely due to a poorly designed miner in the blockchain there are a few blocks where the coinbase is less than subsidy + fees and thus coins have already been destroyed.

This sounds like an edge case; so once they have been mined can they be destroyed?

They are destroyed in the mining if the coinbase reward is less than the current block subsidy + fees.

Invalid Block:
coinbase reward > block subsidy + tx fees

Valid block & no coins destroyed:
coinbase reward = block subsidy + tx fees

Valid block & coins destroyed:
coinbase reward < block subsidy + tx fees

When bitcoins are lost you can consider them destroyed because there is absolutely no way to restore them.
But you don't need that to prove that bitcoins aren't tulips  ::)

how do you know there's even a private address associated with that wallet?  where did they calculate that address from?

Why except the possibility of being lost?  Yes they are very destructible, maybe not rotting exactly, but they are only as safe and secure as the integrity of the holders IT.  Fire, flood, HD crash, data corruption, theft or loss of hardware, forgetfulness (of presence of private key or passwords) can all effectively destroy Bitcoins. 

Watch that address. If you see someone spending its outputs, it is probably time to get out of bitcoin.

Every transaction destroys old outputs and creates new ones to replace them.

The act of spending bitcoins destroys them.

"Nearly every 256-bit number is a valid private key. Specifically, any 256-bit number between 0x1 and 0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4141 is a valid private key." -bitcoin wiki (https://en.bitcoin.it/wiki/Private_key)

If you know hexadecimal, then you can convert the above to hexadecimal and verify if it is a valid key with some (theoretical) private key associated with it.

An address is a hash of the public key (w/ checksum) not the public key itself.

It is entirely possible that there is no public key which produces the address above.

Well, coins sent to an address for which nobody has the priv key are practically destroyed. That's because the day it becomes possible to recover these coins is the day the crypto that holds all the bitcoins becomes broken and all the coins everywhere become as good as destroyed.

Unless decades prior Bitcoin was expanded to include new stronger address types.  Say tomorrow there is a theoretical flaw in ECDSA which would allow an attacker with billions of dollars to break a ECDSA keypair.  It still wouldn't be a direct threat to Bitcoin but attacks always get cheaper and better over time so a new address type is created which provides more security and over the following decade people move funds into the newer address types.  It is possible someday when it becomes economical to attack those "old" address types the only funds left will be ones involving lost keys.

If that did happen, miners would likely stop relaying transactions from the old address type before it became economical to harvest them en masse.

Are you sure that this wallet does not have a private key?

Because it was created as a donation wallet by someone named holgero, and I can see a 0.559 BTC donation coming to it two months ago.

Why?  Also 100.000000000000000000000000000000000000000000% of miners?  Even if the tx includes a giant tx fee? I doubt it

Miners would be the ones breaking old insecure keys.

No one has a computer or vanity generator powerful enough to create a bitcoin address with corresponding private key with such a long prefix in a timely manner. Someone just made an address and attached a proper checksum to make it valid.

Of course not voluntarily. In the scenario where ECDSA has been broken and its use has long since been phased out, there would doubtless eventually be a discussion among the community about whether to make a hard-forking change that after block X such accounts cannot be spent from. This would of course be a massive heated debate that we don't need to have here and now, but it's my opinion that imposing a rule preventing such spends would be for the good of the community, and I'd go out on a limb and speculate that that would end up being the consensus - although if mining hardware at such a time were capable of the cracking operation, miners' personal interests may prevail and a lot of hashing power would end up moving from safeguarding the network to cracking keys.

Well the nice thing about ASICs is the hashpower can't "move" to other tasks.   The hardware is also a sunk cost, it really never makes sense to turn off an ASIC once purchased until it is no longer profitable to run, at which point it would be turned off no matter what.

i don't see how you could say they are indestructible.. the blockchain relies on the users who download them. it could go FUBAR with a 51% attack, no?

I can't remember clearly but didn't someone once accept a 10 BTC block subsidy instead of the usual 50 BTC as a test?

Do you have any examples of such blocks?  I can't seem to find any with a quick web search.  If not, don't worry; if I care enough I'll write a script.

I destroyed 0.00000004 BTC in this transaction:

https://blockchain.info/tx/bf40e4a1c2546747bc800a085e7145d921a9f402aaf4040c155ff5d0df9cc999

Let me put it that way. If i ever see this address sending bitcoins to anyone i 'll sell all my coins the very next second.

Yes. Once mined they are indestructible.

Being abstract constructs, Bitcoins are no more destructible than the number 2 is destructible.
They can only be transferred.
You cannot "unmine" them.

A bitcoin however can be taken out of circulation like every other means of exchange if the owner just refuses to spend it. Or the wallet is lost. But there is no equivalent of burning a $1 note in bitcoins.

Can someone correct me if I'm wrong?

Your wrong.  I already pointed out how through mining coins can be destroyed permanently.

Are you referring to pools?
I'm new to this can you explain the subsidy and fees?
I was under the impression subsidy and fees would be transferred to a node for solving the block or something.
MY question is simple, aren't those bitcoins transferred to some other client on the node?

The rules only require the amount paid to the block solver to be LESS THAN (but not necessarily equal to) the total tx fees + block subsidy.

I think this may need further clarification for the noobs:

When a miner (or pool of miners) successfully mines a block the protocol lets them put a special transaction into the block that gives them 25 BTC "out of thin air" - this is where Bitcoins come from.

What D&T is saying is that the protocol specifies that in each block the miner or pool who first mines it gets to give themselves up to 25 BTC.  So if they give themselves only 10 BTC then 15 BTC are lost forever because they will never be mined.

It would be silly for a pool or miner to do this to themselves but if they did that block is done and it cannot be changed.  Since it only created 10 out of the 25 possible BTC for that block the total number of BTC that will ever be created is now 15 less.

Make sense?

Thanks BurtW.  However it is more than just the subsidy.  The same concept applies to fees as well.

The protocol simply requires the value of the coinbase (reward to miner) to be LESS THAN the amount of fees + block subsidy.   So imagine in the future when block subsidy is zero and fees and a block has x BTC in fees.  A miner solves the block and has the coinbase set to zero.  12 BTC of existing coins will be permanently destroyed.  Users will pay 12 BTC in fees and the miner won't collect them.  This can happen at any time.

Lets look at a recent block.
https://blockchain.info/block-index/445116/000000000000000564bb70e7d7b56c9e0e399aea3c82ec84154f84aee94cc7cd

The current block subsidy = 25 BTC
The value of tx fees in block = 0.01678413 BTC
The amount paid to miner (see first tx) = 25.01678413 BTC.

So this is obviously a valid block.  
If the coinbase was 25.01678414 BTC or higher it would be an invalid block.
However if the coinbase was 25.01678412 BTC or less it would still be a valid block and one or more satoshis would be permanently "deleted".

There are at least six blocks where the coinbase payout is less than block subsidy + fees, so some coins have already been destroyed in this manner although I assume this was due to a miner error rather than any malicious intent.  I am not particularly worried about it but the answer to the question "are bitcoins indestructible?" the answer is a definitive no.

How do people know somebody doesn't have the private key to that address all along and they're just sitting on the coins?

What does "coinbase reward mean"?

Because the person that created the address 1BitcoinEaterAddressDontSendf59kuE never had the private key.  They simply started with the string "1BitcoinEaterAddressDontSend" and then added the correct checksum "f59kuE" onto the end of the string (it is a bit more complicated than that but you get the point).

Since they never had the private key no one will ever have the private key so any coins sent to that address are lost forever.

inb4 somebody quibbles about the odds not being exactly zero.

As they are digital I am going to assume you do not mean indestructible in the literal sense of the word. They cannot practically be bruteforced, nor can they be sent to an invalid address. So the only way they can be lost is via human error. One has to forget where they left them, or forget the key to access them, or send them to a random address someone else or no-one has control over. If you simply take care when dealing with them then yes, they are indestructible as long as you use common sense.

They can be destroyed in the block creation process (mining).  They can be destroyed so they are not indestructible.

It's going to take awhile for bitcoins to be destroyed by mining. Which miner in their right mind would do that? Which pool? And before anything major happens, only a few bitcoins will be destroyed that way, maybe at most a day's worth, before everyone knows about it, then all the miners and pools will fix it.

As far as everyone is concerned, we will still see about 11.8 million coins by the end of this year (2013) and about 20 million coins before the year 2025.

The few that will be destroyed by mining less than the block reward and subsidy and fees... Well, no one is going to do them on purpose, and even if someone intended to do them on purpose they would only waste their time and money.

Whether or not miners make the coinbase = Subsidy + Fees, I think it's fair to say that bitcoins sent as transaction fees are destroyed.

Well by that logic all coins are destroyed in any tx (and an equal number of new ones created).  However under normal circumstances there is no NET coins destroyed.   Tx inputs = Tx Outputs + Miner fee.   As long as miner pays out those fees in coinbase then no net coins are destroyed so making a distinction that tx fee outputs are destroyed but not normal tx outputs is without merit.

That is not true because you can find that lost coins - by accident, for instance - when you create a bitcoin address.
It is very unlikely and a bit like searching for gold in the desert but still, you know, you can find a grain of gold in a beach of sand, can't you? I mean, it is possible within the laws of Physics...

Which wasn't the question asked.

The question was are bitcoins indestructible?  The answer is no.  It would be like asking is cash indestructible?  and someone answers no you can destroy it by burning it then saying, well who would do that?  I don't know who would do that and for what purpose, it may never be done except in accident however none of that changes the answer to the question "are bitcoins indestructible?", that answer beyond any debate is definitively ... no.

Yes. Correct. I just thought I'd add a little to the discussion. It's not a big issue for almost everyone else. I don't see more than a few thousand coins ever being destroyed that way, even if intentional.

Massively unlikely though given that the pigeonhole priniciple shows that there are on average 2^96 public keys mapping to each bitcoin address.  Quite unlikely (read: impossible) any address misses all of its expected 2^96 hits.

Ouch....  :o

Luckily it only has 1.6 BTC right?  Or did I look that up wrong?

https://blockchain.info/address/1BitcoinEaterAddressDontSendf59kuE

1.60652869 BTC ($ 1,420.11 at the time of this post)

Bitcoins are very abstract.  The definition of "destroyed" gets fuzzy here.

Blocks claiming less than the full possible reward most closely fit, in my opinion, the concept of destroyed.  These coins can only be recovered by a change in the protocol.*  Also in this category is the permanently unspendable coins from one or the other of the two blocks that had identical coinbase transactions.

Coins sent to keyless addresses are the second best fit.  No one has ever known a privkey that could redeem those coins, and so we have no reason to believe that such a key exists.

Coins sent to keys that were generated but then lost is the weakest fit.  We know that a key to that address has existed in the past, and so there is every reason to believe that the key could be found again.  Thermodynamics blocks us from doing so, but math itself doesn't bar our way.

* Such a change may not be completely crazy, but is still really unlikely.  It wouldn't hurt much to allow miners to claim some fraction of the coins lost through this method in the past.  Of course, it wouldn't help much either...

What is "coinbase"?  How do you get a block that has "less than the full possible reward"?



How do you get a valid address with a key that "doesn't exist"?  How is an address where nobody ever had the key any different than an address where somebody had the key but has really absolutely permanently lost it.  Let's say they generated it in volatile memory, wrote it on paper, shut down the computer and then burned the paper...  how is that any different to a valid address where nobody ever really had the key?

And on that note how do you make a valid address but without ever getting the private key?  Aren't valid addresses generated from private keys?  I mean when I import a private key it knows the address without me telling it just from the private key.

Normally, a transaction has 1+ inputs and 1+ outputs.  Each block has a special transaction in it that has no inputs, which is used to reward the miner.  Where the input would normally be is a freeform field named "coinbase".  The term is also commonly (but incorrectly) used to mean the generation transaction itself.  (My bad.)

Once upon a time, a guy mined two blocks using the exact same address for the reward.  Both of those generation transactions were identical, so they had the same hash.  In bitcoin, the hash is a, ahem, "unique" identifier, so spending one of them spends both of them.  Thus, 50 coins "destroyed".

This won't happen again because blocks are now required to have their height in the coinbase field, which makes them unique even if they are otherwise identical.

And the network only checks that the generation transaction's value is less than or equal to the subsidy + the fees.  Nothing stops you from making a block that claims less than the full reward, but doing so is silly, and nowadays, expensive.  A few blocks in the past, however, claimed less reward than they could have, so the worldwide total will be slightly less than it could have been.


Any 256-bit string is a private key.  Multiply (in EC math) G by that private key, and you have a public key.  Hash that public key in a particular way and encode it and you have an address.  Neither the multiplication nor the hashing are reversible.  You can pick a random number, hash it and see what the address would have been, even though you don't have a private key that would work for it.  Or, you can skip right to the end and make an address without knowing what the public key should have been, much less the private key.

The address hash is 160 bits.  We do know that for every input, there is one output, but we don't know that for every possible 160-bit number there is necessarily an input that creates it.  The address in my hash, for example, has a pubkey that can be hashed to create it.  But we don't know if there is any pubkey that hashes down to the bitcoin eater address.

I'm not sure if EC multiplication has the same property or not.  I *think* that for every valid public key, we know that some private key matches it even if we don't know what that private key is.  A proper cryptographer could answer that for sure.

I did this up thread here:

https://bitcointalk.org/index.php?topic=358010.msg3849442#msg3849442

And explained it to you up thread here:

https://bitcointalk.org/index.php?topic=358010.msg3858534#msg3858534

so... if we aimed all the Hashing power of the Bitcoin network on one address it would take 500 million years? Hey man It's only a matter of time before insane quantum computers just start cracking the codes by the second. I can imagine this will happen one day, when the Bitcoin network migrates to a new protocol based on quantum security. Those computers will tear Bitcoin apart when they finally are able to produce them in mass, and start migrating all the accounts to a new system like a block reward, Or just like the free market migrate by choice to something safer.

Quantum computers do not appear to be particularly adept at hashing.

Guys, you are missing OP_RETURN. If the output of a bitcoin transaction is "OP_RETURN" then the coins are impossible to spend.

Oh shit, that's right.  There are actually a whole bunch of coins locked up in scripts that have no possible solution.  Not just OP_RETURN, but also garbage from buggy systems over the years.

Well in theory at least the number of coins destroyed in this way could be calculated by scanning all unspent output.  Knowing this number you could then subtract it from the ending total and get a slightly more accurate ending total.

Could someone please point me to a good description of bitcoin mining for someone that has studied first year uni maths. ie not too dumbed down but not too advanced either.

More specifically, using Grover's Algorithm, the time taken to find a preimage of a hash (i.e. a reverse hash) is the square-root of the time for a classical attack. e.g. a 256-bit hash becomes like a 128-bit hash. It's not considered a big problem since the times are still very long.

Not to wander too far off topic, but Grover's solves circuits.  Circuit means the function must be completely unrolled in both time and space, so that there is no memory and no iteration, just logic gates.  A circuit for SHA-256 is far beyond our capabilities, much less double SHA-256.  I'm not sure we are even capable of designing such a thing.

Oh, and did I mention that all those trillions (quadrillions?  pentillions?  who knows?) of logic gates have to be reversible quantum gates?  And that they all have to be kept coherent?

sounds like a great design for a hardware wallet.

My question is how do you know what to add to the end?

Compute the checksum of the pubkeyhash. 

https://en.bitcoin.it/wiki/Technical_background_of_Bitcoin_addresses
Take a look at steps #4 to #7.

I'm pretty sure someone will figure bitcoin's cryptograhy in the future. Maybe the second coming of Jesus would?  :P

Actually - given enough time - is it theoretically possible to crack the private key to that address?

I mean in the future computers will be 1000x more powerful than they are today.

Will our brains be blown out of our bodies?

No.

https://images.weserv.nl/?url=i.imgur.com/VjtG3.jpg&fnr

I think the answer is yes. Theoretically. Enough time means a few billion years using the latest computer technology a million years in the future, that is a trillion times faster than all the fastest super computers combined in existence.

Practically, No.

But we're being pedantic here.

See Syke's answer.

Also:

private key is a 256 bit integer.
public key is a pair of 256 bit integers giving the (x,y) coordinates of a point, or a single 256 bit x coordinate and a parity bit used to reconstruct y.
address is a hash of the public key.

The bitcoin eater was made at step 3.  Because it was made at step 3, we don't know if there are any points on our curve that can be hashed to give that address.  This point isn't well understood around here.

i don't see how you could say they are indestructible.. the blockchain relies on the users who download them. it could go FUBAR with a 51% attack, no?

This is something that is addressed many times before. While the obvious answer is yes there are some physical limitations that don't allow something like it to happen. In quantum physics though seems possible.

Physics says NO.  READ the post right above yours.

I believe that given there will be on average 2⁹⁶ public keys per Bitcoin address we can be fairly certain there is at least one public key that hashes to any given address, including this one.

You are assuming a uniform distribution in the output of the hash functions.  This is something that we hope is true, but don't really know.

That is why I said on average and fairly certain.

Exactly.  As the quote in the "star image" was mine, I want to avoid it being taken out of context.  As you point out if you can't go through the wall there may be other ways around it.   The quote only deals with brute forcing a 256 bit key (and subsequently to writing that quote I have learned that a 256 bit ECDSA key only has 128 bit strength against brute force attack although that doesn't materially change the scenario in the quote).  It only deals with a brute force attack and I wrote it because I got tired of all the "what if computers get faster can someone hack Bitcoin questions".  Still it is important to keep in mind that there are other attack vectors which don't deal with a classical brute force (and the physics problems that accompany it).

If you wanted to gain access to coins at a random Bitcoin address there are three attack vectors:

• Brute force attack on all the private keys used in the Bitcoin network = infeasible given the time and energy requirements (the "star quote").
• Exploit a cryptographic flaw in ECDSA, RIPEMD-160, and/or SHA-256 = no such known flaw exists at this time and may not exist in our lifetime.
• Use a general Purpose quantum computer capable of implementing Shor's algorithm = may not ever be possible or if possible the time until a GPQC with 40,000+ qubits is indeterminable.

All three are infeasible right now, only the first one is beyond the limits of physics the other two simply don't exist right now.  Maybe they will exist next year, maybe not for a thousand years but we do know that they are possible on a long enough timeline.  The good news is that Bitcoin is extensible and long before either cryptoanalysis or quantum computing make an attack economical or practical Bitcoin can be extended to new stronger address types including ones which are quantum computing resistant.  People can transfer funds to the new addresses and avoid the attack vector (for another century or so).  Of course funds for which there is no known private key ("lost coins") could at least in theory be reclaimed because they won't be moved to the stronger address scheme but it won't be as some incorrectly believe "because computers get faster".

Agreed.  

It is possible that SHA-256 or RIPEMD-160 have undesirable characteristics which result in a non uniform distribution of messages to digests but at this time both algorithms are seen as a good approximation of the random oracle so there is no reason to assume that until facts suggest otherwise.  Even if future cryptanalysis shows that they have a non-uniform distribution it would have to be incredibly non-uniform to affect the probability that at least one valid PubKey hashes to that PubKeyHash in any meaningful way.  You corrected me on a similar statement I on reflection I agree.

Saying we "hope" is exaggerated; it is like saying Bitcoin users are just hoping nobody generates their private key and steals their coins thus the whole Bitcoin network runs on "hope".  Cryptography is always based on probabilities however we use really really reallly really really large numbers so the probability of certain events approaches 1 or approaches 0 but never is known to be 1 or 0 before the event.    In theory I could randomly bang on my keyboard right now and produce a private key which allows me to impersonate Google's SSL cert on the first attempt.  It "could" happen but Google doesn't really need to "hope" it doesn't happen because while the odds are not 0 they are for all practical purposes ~0.

Of course I think the best way to sum it up is that if I ever notice funds are transferred out of the "Bitcoin Eater" address I am selling coins first and asking questions second. It is a good canary in the Bitcoin mine. :)

Yes, Bitcoins can be destroyed. The release of a world wide Electro-Magtnetic Pulse could destroy them all, but bitcoin would be the least of our worries.  :P

The difference is that an address derived from a key is known to have a matching pubkey and a matching privkey.  If we ignore physics and math, someone searching all possible private keys will find at least one that matches the address in my signature, eventually.  Will they also find a key that can spend the bitcoin eater?  How about the key to 1111111111111111111114oLvT2 (https://blockchain.info/address/1111111111111111111114oLvT2) or 1QLbz7JHiBTspS962RLKV8GndWFwi5j6Qr (https://blockchain.info/address/1QLbz7JHiBTspS962RLKV8GndWFwi5j6Qr)?  No one knows.

Those last two should make you pause, and that is why I consider coins sent to them to have a higher level of destroyedness than bitcoins sent to addresses for which the key has merely been lost.


Indeed.

I totally agree, but those addresses are special corner cases.  They are in a class all by themselves and it would be pretty hard to argue that 1BitcoinEaterAddressDontSendf59kuE belongs to the same class as those two addresses, right?

If you go by Kolmogorov complexity, all zeroes and all ones are the two minima, but the bitcoin eater is much closer to them than it is to "normal" addresses, or even to the best vanity addresses found so far.

Why do we even talk about the bitcoineaterblablabla address? It's an address without the private key like so many others that people lost their keys already  ::)

Because these addresses pertain to the question of the thread.

I don't understand what destructibility has to do with the tulip bulb bubble. That was simply a case of a fashion item based bubble.

The difference is, this bitcoineater address quite possibly does not have an equivalent private key. The ones that people lost, they once had private keys. They just lost them.

It is a fine distinction, true enough, but we are talking about whether or not an intangible idea can be destroyed or not...

It's certain not quite possible that it doesn't have an equivalent private key. So what?

Well, ideas ... can not be destroyed. You can't kill an idea.

I don't know if Bitcoin can be indestructible in a technical sense but they may become outdated as faster more efficient protocols come into place but I don't see this coming for the foreseeable future as it will take at least one generation for Bitcoin to reach it's potential as a payment system over the coming decades. I will be curious to see how things play out and hope to be alive to see some positive changes coming for Bitcoiners all over.

I would say that they are indeed, indestructible.

The topic is morphing from the original question. It seems to me, that bitcoin will stick around just the way it is, and other crypto-currencies will take over, for other functions. I treat bitcoin like a check or bank wire. Takes about 10 minutes to send, an hour just to be sure. But it's there.

The coins are just bits on different HDD's somewhere. If that magnetic information dies, bitcoins are lost.
For that to happen, it would require that everyone having the chain stop using the Internet or at minimum the Bitcoin P2P software all together. What would lead to that is another story. Cataclysms, ultra depreciation, laws and regulations...

Also, when all the 21 million coins will be minted, any transfer will deduct a fee, but no more coins will be generated to cover that. Will that lead to destruction?

Fees do not create or destroy coins. They are simply transfers made from the sender to the miner.

Unlikely. I personally am aware of several copies of the blockchain (albeit weeks or months stale) on HDDs stored in Faraday cages. I doubt this is the only such set -- by a long shot.

What you describe isn't the loss of coins, it is the corruption of all copies of the chain and as a result a loss of all bitcoins everywhere simultaneously.

Individual bitcoin loss can occur, it happens when a wallet key is lost. This creates an orphaned wallet that nobody in the world can access, yet contains coins. The coins still exist, they just cannot be reached by anyone

I just burnt a copy of the blockchain to a DVD. We're now safe from any EM pulses.

Have you tried putting a CD or a DVD in a microwave oven? Put it on high for 3 seconds.

That's probably what an EM pulse would do.

A microwave typically uses a 1300 watts (typically) bulb. Put your hand a foot away from a 100 watt lightbulb, with and without a sheet of paper in between. feel the difference in heat? Imagine it was 13x stronger.

You COULD in theory have an EM pulse so powerful that it would have equivalent energy levels when it strikes your CD despite the square cube law dispersion pattern (and also amped up because a pulse lasts a tiny fraction of a second while microwave cooking takes longer) but an EM pulse that powerful would wipe out all life on the planet.

Your typical "destroy all electronics" EM pulse is a tiny tiny fraction of that amount of power. When it hits conductive metals it creates an electric current which burns away capacitors and transistors and other components of a printed circuit board. The more fine the electronic component is, the more susceptible it is to EMR (unless shielded. A faraday cage would nullify it)

... that being said, some optical media uses metalic dye, which might be conductive.

Yes they are, i think! You cant 'destroy' them just lose them maybe.

Yeah. I tried it before. I got a bunch of old CDs and DVDs which I tested in the microwave after reading about it on the internet. Sparks appear after 3 seconds.

The explanation was, the CD is like a mile long electric wire going around. Current is induced. It sparks. It burns.

http://www.wikihow.com/Microwave-a-CD

http://2.bp.blogspot.com/-hmpxQdPUW8A/UaPCcn1UYiI/AAAAAAAAFMA/_cctVay5cnk/s1600/microwave_cd_04.jpg

A mile long electric wire made of various organic cyanide compounds that you're spreading all around your microwave!

Something I know something about!  The numbers you are looking for are in the last row:

I'm quite sceptical that quantum computers are physically even logically possible to build since the theory is predicated on the flawed Copenhagen interpretation. So I'd say bitcoins can't be counterfeited based on a brute force computing approach given what I have read here.

Everyone have their own opinion regarding the health of bitcoins Mr. DavidZ. In accordance to my views it is surely destructible. In fact these days a lot of tough measures by central banks especially china indicate bitcoin destruction has already began. Some people have seen it while others shall see its destruction soon.

This post is basically off topic.  This thread is discussing technical aspects of Bitcoin - not political.