Several of those are bitcoin exchanges, and they hold other peoples coins in them. The "richest" addres belongs to bitfinex.
Most of those addresses do not belong to rich individuals.

Personally I think that they are crazy. If they were smart they would divide the coins to several addresses. It is safer to have multiple addresses.
If someone succeeded in emptying one address they still would not lose everything.

The only reason to have so much in one address is that it may be good publicity.

The length of encoded text (here the seed) doesn't have anything to do with security of the AES-encryption.
It has as much to do with it than the length of emails in your inbox have to do with the security of your email account password.


The only thing that matters is the length of the encryption key.
And I just pointed out that in Electrum most people use a short encryption key (= password) because the box where you put your key is small and Electrum actually says after 10 characters that the key is Strong.
I know that you can select a very long password, and then it indeed is impossible to crack.

My first Electrum password was "Bitcoin123". Apparently you think that my 10 letter long password has a 88 char (88*8=704bit security) .
What if I encrypt the Bible with my short "Bitcoin123" encryption key? Would the security level be 3,566,480 letters = 28531840 bits?  Whooooa. why hasn't anyone discovered this before  
(Actually I googled it and the Bible does have 3566480 letters.)

If, and it is a big IF, the encryption password is short (and nonrandom) then it can be probably cracked if there is some knowledge of the password format.  

If you start testing from 0 and finally find the right password after checking every possible combination of 1-10 characters it has nothing to do with 88 (704 bits) character long text that has been encrypted with the password. The OP has the seed and the encrypted seed, so you can check keys one by one and you know when you have it right..

PS: I will say it once again. OP is not trying to crack the Electrum seed. He is trying to crack his password, which is probably only 8-12 chars long.

Probably its possible. You are wrong in assuming that the "seed" is long.
Usually most people use quite SHORT passwords as an electrum password, which is not the same as the long wallet seed btw.

When choosing a password, the current electrum says that, password length of:

• <7 characters is Weak
• 7 characters is Medium strength
• 10 characters is Strong.

I would assume that most people choose a password of 8-12 characters, and many use the length of exactly 10 characters, because that is where electrum says that password is strong.  Not sure what password lenght electrum recommended in 2013 (could have been shorter)

The problem here is finding the ~10 characters long password used in AES encrypting the seed and wallet. And 10 characters long password should be SOLVABLE.
(Its a completely different problem than guessing the seed of the wallet, which has a strength of  2^128 bits which indeed is practically impossible.)

And in addition the OP already KNOWS the seed. He is only missing the wallet password.

Sage55: Do yo have any more information about your password. How long is it? what special characters it has? Do yo know if it has a certain word in it?

Wow. In 2008 bitcoin really was worthless.
He must have been the FIRST. Seems he started even before Satoshi himself.
 

In that case, I started already in 2005 !!!

Of course it would affect bitcoin.
A successful attack, where someone steals huge amounts of coins from an exchange would be very bad for the value of bitcoin. Remember MtGox?
Such attack would erode peoples trust in bitcoin and crash its value even if it would be caused by exchanges bad security.

 

So it could happen to you too  
there is a virus that changes copy/pasted bitcoin addresses in the clipboard.
If you do not read the address carefully after pasting, then the address you paste can be different than the address you copied.

Quite sneaky.

Are you in a hurry?

You could wait for a cheaper moment, or make the transaction with smaller fee.

Eventually it will be included in a block.

You can check the current fee from here:
https://bitcoinfees.21.co/

No risk for you private key. (if you create the transaction on an off line machine. Newer put your private key to a browser!)
The signed transaction does not contain your private key. It only contains your public key and a verification hash that verifies that you control the private key.

Yep. you can create the raw transaction in most wallets. I do not know if it is possible to do in bitcoin core without downloading the whole blockchain though. (how would it know you have coins otherwise?)

It's the value of the moduli. It is the biggest number in the curve secp256k1 that bitcoin uses.
=2^256-2^32-2^9-2^8-2^7-2^6-2^4-1

If your generated private key is bigger than that, then you have to subtract that number from your generated key as many times as necessary, until it becomes smaller than that number.

The security of bitcoin depends on big numbers. That is the reason why the moduli has to be so big.

https://en.bitcoin.it/wiki/Secp256k1

Quite risky!
I have many usb sticks, external hd:s and some computers. I would not count on my family to actually have time to go through every usb stick they find. I certainly do not.

Why not just tell them, that you have bitcoins, and that there is a hidden USB to look for.... Or give more specific instructions.
Or store a copy in a bank safety box or something.

Nice idea to encrypt it with something that only persons who know you can access  

It is possible to track transaction in the blockchain, BUT and it it a big but, You can never know if the coins are still owned by the person who stole them, or if he has already sold them.

Any transfer can be a transfer to a new owners address, or transfer between the same owners addresses. How could you know?

It is possible to sell bitcoins outside of exchanges too. Eg. in localbitcoins or net forums. 

Actually some coins from January 2009 and early 2009 has already been moved, and it did not affect the price at all.

How can anyone know with 100% certainty if those really were Satoshis coins or not?
At least if they are not from the first 50-100 blocks..

You could invent a nice rule on how to generate a new private key from your private key.

Example.
You could take your private key an multiply it by any number (for example: 36453278)  to get the next private key then multiply that to get the next one and so on.  You can do the multiply as many times as you want to. to generate as many addresses as you need.

Just remember that we are dealing with modular arithmetic, so you need to take a mod from the result, so that it wont get bigger than the maximum allowed value.

eg:

(privkey1*36453278) mod 115792089237316195423570985008687907853269984665640564039457584007908834671663

That is basically what HD wallets do to generate many private keys from one. Except, they use a bit more complicated algorithm and sha256 hash on each result so that even a small change will create a completely different private key.

The advantage of this kind of approach is that you only need to backup your original private key and the multiplier, and not a huge list of different private keys.

Copay is an easy and nice android wallet, that supports multiSig and you can enable pin or fingerprint lock in the app too.

Is it safer to use 2 different random number generators in generating a secure private key?

If your RNG is truly random then that is excellent, and you do not need anything else in generating your private key. But how can you know?

If you suspect that one or the other RNG is perhaps not truly random, or that it might be somehow compromised, wouldn't it be a good idea to generate 2 private keys in different ways, and then XOR them together to get one that is really random?

I am planning to use bitaddress.org and urandom()  (=operating system RNG) to get 2 256bit random numbers and then XOR them together.

The problem with bittaddress.org is that it is someone else's code. I do not know if there is a bag-door/vulnerability in it. I do know bittaddress.org is well trusted, but what if a hacker has just changed the code in the web-page?
Problem with urandom() is that when it has enough entropy it is a good RNG, but if it doesn't have enough entropy, then it can give insecure random numbers. And you can not know., because urandom() does not tell you if entropy is low.

In my opinion combining these 2 by using XOR should give reliable private key even if one of the RNG:s is not as random as it should.

Opinions?

I have been playing with copay in testnet, and at least the testnet version does not create a multiSig address, if you don''t want to specifically create a multiSig address.

If copay would create a multiSig address in secret and hide the 2nd private key, that would be really bad, because then you would not control your own bitcoins. And if copay servers would then one day vanish from the net you would lose your coins.

Luckily that is not the case. Copay is an easy wallet that works well. Although I prefer Electrum.

Strange that Copay needs internet connection when creating the wallet. That should be fixed!

Would be great, if there was an official pruned blockchain available for download.
The pruned version could be made for example from block 450000 and correctness could be verified with a hash sum.

The size of pruned blockchain is apparently about 8GB currently.

At some stage we will have to go that way or the blockchain will grow too big to be practical. 

Are you trying to ask where we keep our private keys and seeds?
My backup for my 1000000BTC:s is on my backyard dug behind the large tree, and my address is xxxxxxx. Why do you want to know? 

On a more serious note,
Remember to protect them from fire too. At least one copy should be in a different location.

 

This is different question, so you should have posted a new thread, but here is one solution for your friend:

You do not have to buy a new computer. You can just get your private keys from the old bitcoin-core without needing to download the whole blockchain, and then import those keys to electrum, which will work in the old machine.

More info here:
https://bitcointalk.org/index.php?topic=2250550.msg22754328#msg22754328

Sad to hear about your loss.

Completely unrelated to the theft, but why do you reuse your addresses?