Backing-up Bitcoins within Bitcoin itself...

[I.Goldstein]

Would it be of any benefit to encrypt a Bitcoin private key in an algorithm of your choosing then place its output in the blockchain itself? You could access the Bitcoins at any time. You just need the password for your encryption.

Is there any software that allows us to write into the blockchain these days? I know the original versions of Bitcoin had a messaging function.

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[DeathAndTaxes]

If you have a passphrase simply use a deterministic wallet.

Also the wording of your question is weird.  You can't backup a bitcoin.  Every bitcoin every minted is already in the block chain.  You simply need to backup a private key.

You could back it up in the blockchain but you gain nothing over conventional backup to the cloud or determisitic wallet.

[elggawf]

If you want to store arbitrary shit in a blockchain, just use namecoin. Merged mining's blowing up so I'm pretty sure namecoin's not going anywhere, it's free to later update the information (or add new information to the same domain), and the cost to actually register is minimal (at current NMC prices and domain cost you're looking at around 0.2BTC or 60c or so to register a new namecoin domain).

[nmat]

Is there any software that allows us to write into the blockchain these days? I know the original versions of Bitcoin had a messaging function.

https://bitcointalk.org/index.php?topic=47283.0

[wareen]

You could back it up in the blockchain but you gain nothing over conventional backup to the cloud or determisitic wallet.

Well, data in the cloud can be accidentally deleted, your account could be hacked or your "cloud" might go out of business.
Additionaly, a backup of a private key in the blockchain would have the nice property of being exactly available as long as it is useful (ie. it lives and dies with Bitcoin).

I like the idea of a backup being embedded in the blockchain. One could even use the data in the blockchain for some kind of steganographic storage of a key/passphrase. Since it isn't too hard to include arbitrary data in the blockchain, everybody can easily cook up his own scheme - only your imagination is the limit.

[DeathAndTaxes]

Except his plan was to backup an ENCRYPTED copy of the private key.  If he loses the key then it being in the block chain is useless.  If he backup the key he is right back to the issue of keeping alternate backups.

With a deterministic wallet you can create thousands (millions if you need them) of addresses from a single passphrase.  You simply need to backup the passphrase (preferably offline).  I use a deterministic wallet and have memorized the passphrase and I keep a copy in my safety deposit box.  I have no other backups of my wallet.dat and I am very confident in my ability to recover any balances in the event of a data loss.

[wareen]

Except his plan was to backup an ENCRYPTED copy of the private key.  If he loses the key then it being in the block chain is useless.  If he backup the key he is right back to the issue of keeping alternate backups.

Putting an encrypted private key in the blockchain has advantages over putting the encrypted private key in the cloud as you suggested, but you are right of course, in that a deterministic wallet based on a passphrase serves pretty much the same purpose.

[elggawf]

The wording of his question is weird because Atlas doesn't know how to speak English.

Sometimes I'm not sure anymore whether your snark is due to genuine disgust at what you see, or because you just desperately want to be accepted by goons.

[Portnoy]

Also the wording of your question is weird.

The wording of his question is weird because Atlas doesn't know how to speak English.

Why don't you address the ideas expressed instead always getting into these threads just to do personal attacks? 

[teflone]

Also the wording of your question is weird.

The wording of his question is weird because Atlas doesn't know how to speak English.

Why don't you address the ideas expressed instead always getting into these threads just to do personal attacks? 

Yes!..

To Matthew everyone is Atlas.. 

[I.Goldstein]

Where can I find a text editor that encrypts in SHA512?

[elggawf]

Where can I find a text editor that encrypts in SHA512?

SHA512 is not encryption it's a hashing mechanism. The difference is that hashes are not reversible, SHA is not what you want for storing your private key in the blockchain.

[MatthewLM]

I've talked to people on #bitcoin IRC channel and they said that you cannot guarantee additional data will be included in the blockchain by miners so some sort of server based or side-line p2p solution would be best for sending messages and encrypted data of sorts.

If people use a deterministic wallet they need to be careful of collision problems. It forces highly unique and long pass-phrases, you have to remember.

[DeathAndTaxes]

Where can I find a text editor that encrypts in SHA512?

SHA (all variants), MD5, RIPEMD, Tiger, Whirpool are all hashing algorithms. 
Something -> cryptographic hashing function -> hash.

All cryptographically strong hashing functions are irreversible.  Meaning you can go something -> hash but not hash -> something.

To store something encrypted in the block chain you want a symmetric encryption cipher.  Some examples are:
Twofish, Serpent, AES, Blowfish, CAST5, RC4, 3DES, and IDEA.

Symmetric encryption algorithms are reversible (if you have the key) i.e.
Plain Text -> encryption function (w/ key) -> Cipher Text
Cipher Text -> encryption function (w/ same key) -> Plain Text

Unless you have some specific reason to use a different algorithm AES is a good choice.  It is strong, has no known vulnerabilities, and has been extensively tested and used worldwide.  The US govt requires AES to encrypt SECRET and TOP SECRET documents.

[elggawf]

The disgust is very real. I'm tired of supporting a community who consists mostly of money grubbing has-beens, no-talent 'home makers', and over-the-top libertarians. I was happy considering Bitcoin an alternative to Paypal but some people just want to try to rule the world with maccaroni craft guns and tanks.

Yeah, I can, to an extent, empathize with that. Lots of people on this forum still seem to think that any questionable business idea with Bitcoin attached is an instant-hit. In fact most of the forum just seems to think Atlas can do no right, but I would almost bet that if you took one of Atlas' ideas and had another, more respected member of the forum propose it, you'd have no shortage of cheerleaders patting the OP on the back and telling them what a great idea it is.

I still think Atlas is a terrible communicator. I don't believe he actually "thinks" in the language he does, I think he uses pseudo-intellectual babble and authoritative phrasing to compensate for something. But cut the kid some slack, it sounds like he's actually trying to work at something - the sooner he realizes that he needs to try and fail (by which I mean actually try something, rather than proposing it and expecting to get credit solely for being the ideas man) a few times before he discovers something that can work.

But I just don't see the sense in making a whipping boy of Atlas for no good reason. When he does/says something dumb, call him out on it for sure - but being nasty for no good reason is just poor etiquette.

[astana]

Trust me if the NSA wanted to crack bitcoin they would in a day. Blowfish or Serpant will just annoy them for 30 minutes while they get another cup of coffee.

[tvbcof]

Trust me if the NSA wanted to crack bitcoin they would in a day. Blowfish or Serpant will just annoy them for 30 minutes while they get another cup of coffee.

I actually doubt that this is the case at this time, and it sounds to me like speculation (particularly as anyone who knew what they were talking about would not be flapping their gums on this board.)  An academic who cracks Blowfish, for instance, and particularly in a practical way would be about as famous as they wish to be.  I doubt that anyone in the NSA puts their pants on much differently than anyone anyone in the top levels of academia, and they probably have limited control over the info that gets out (which could well be why the MD5 work surfaced in China.)

[DiaperedDynamo]

Atlas, I thought you were banned.

[DeathAndTaxes]

Trust me if the NSA wanted to crack bitcoin they would in a day. Blowfish or Serpant will just annoy them for 30 minutes while they get another cup of coffee.

Sure.  You know something that tens of thousands of cryptography experts around the world don't.

There is no brute force method to crack blowfish or serpant.  The sun would burn out before you had a 1% chance of getting valid key, even if every computer on the planet tries a billion keys a second and did nothing else for next 5 billion years.


Now there may (can't disprove a negative) be a cryptographic flaw BUT for your statement to be true three things would need to be true.

1) This cryptographic flaw hasn't been found by any non-NSA cryptographic expert in the entire world (despite many of them looking for a decade)
2) This cryptographic flaw HAS been found by the NSA despite the NSA having <1% of all cryptgrophers in the world on their payroll
3) The NSA has been able to keep this a secret from everyone on the planet ... except you.

so Occam's razor says you are full of shit.