Secret Information via Blockchain?

[bitone]

Short Question:

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the blockchain?

Thanks!

[odolvlobo]

A small amount of information can be stored in the block chain using an OP_RETURN transaction.

[cryptoheadd]

Is there any other token?
Other than Bitcoin, that's leveraging blockchain to transfer information?

[unamis76]

Short Question:

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the blockchain?

Thanks!

A small amount of information can be stored in the block chain using an OP_RETURN transaction.

And encrypting said message

One can use services like CryptoGraffiti to easily embed messages on the blockchain.

[--Encrypted--]

as said above by odolvlobo and unamis76. but I think that's kind of impractical because Bob would have to know the transaction hash or having the transaction sent to his address. might as well go without the blockchain.

oh. and the "secret" letter can be seen by anyone that have the transaction hash. forever.

[GreenBits]

Short Question:

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the blockchain?

Thanks!

this isnt the best method (mem limits), but yes, there are services like the aforementioned that can embed messages in the blockchain.

with that being said, much easier to publically blast a coded message (https://en.wikipedia.org/wiki/Numbers_station) or send an encrypted message. Hiding in plain site isn't the best choice for information that is highly sensitive.

[harrymmmm]

Short Question:

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the blockchain?

Thanks!

Why the need for the blockchain?

1) just a secret message transfer:
bob publishes his public key, alice encrypts the message to that key and sends to bob.

2) a secret message transfer with some deniability for both:
as in (1) except alice transfers encrypted message to a dropbox like mailinator

Use of a blockchain would be indicated if you wanted the message to remain around forever, immutable. 
Do you really need this? Possibly you only need the hash of the message to be kept immutable forever?

[cjmoles]

It can be done....and much more.  But, my question would be: is there a more efficient way to send and preserve communications that wouldn't bloat the block chain ledger?  There are several unnecessary messages already bloating the ledger (photos and quotes of Nelson Mandella, frivolous code...etc)¹; however, there is some amount of utility to the practice such as; copyright posterity, identification verification, and such....


1. Citation here

[The Arcitect]

Not possible. Anything can be cracked with enough motivation and know how.
There is evidence all over the internet you just have to know where to find it.

[Evildrum]

@cjmoles - Excellent link, appreciate reading all the wacky things people have done.
::::::::::::::::::::::::::::::::::::::::''''''':':::::::::

So does adding stuff slow down the transaction as well? I see it takes up more room but does it confirm slower!

[jacobmayes94]

Depends what fee you attached to the transaction? A higher fee would give a miner more incentive to include the larger TX.

[mookid]

Some people argue that services like CryptoGraffiti are bad for Bitcoin in general, the Blockchain size is growing, and embedding messages on it is not helping, every node in the world will have to carry your message to support the blockchain.
This is a waste of space, nodes don't get paid, and yet, they have to store your transactions in their hard drives.

[dothebeats]

I think email is a better way to send secret information.
As i know, some president use email to send/receive sensitive information.

Also easy to intercept, without proper encryption. In the case of sending it via blockchain, everyone who knows the tx hash would also know what message was embedded within that tx, so no, that's not so secret at all.

[gmaxwell]

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the chess game?

[quintiilieo]

Short Question:

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the blockchain?

Thanks!

I think that is impossible to tranfer your message in blockchain. But if you want to transfer a secret message try to use email or facebook. You can create a message there that secretly by downloading the apps that can convert your mesage into other form of message and teach your chatmate that convert it using the app that you use.

[Kakmakr]

I would just use Steganography & Digital Watermarking on a image and post it on one of the popular image hosting sites and then send the url to that image as a message via a transaction to someone else. You could do the same with a link to a youtube video.

You do not need to make it too complex, but if you want it to last, I would insert it into the OP_Return as previously suggested.  

[Wendigo]

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the chess game?

Well maybe they will use a system of letters and numbers that are engraved on the chess board already like from 1 to 8 and from a to h and every other move will have a secret meaning for both parties. Encoding and decoding a letter during a chess game would be fabulous though and for spectators of the game it would be very hard to have a sniff of what has been going on. It's always the best to hide secret information in plain sight right?  

[BitcoinSupremo]

Secret information should be sent via an anonymous and encrypted way, although there have been a lot of hype over TOR that it can be denonymized but the FBI haven't tell us yet how they have done so and in their largest operation by taking down a child-pornography website in deepweb they only managed to get 1300 IP from 22.000 users that means TOR is still the best tool to use together with sigaint email there.
Its not fault of TOR but the users of it not taking precaution if they get their email intercepted. I think TOR is the best option we have yet and TOR developers now have responded they will not let any other attack like this of the FBI happen, they admitted that they saw the attack but let it run as they thought nothing is wrong, now they claim to not let anyone servers when they see alot of activity and they remove it from the network.

As a security paranoia which I am this is the best way to send secret information via TOR and SIGAINT email service. Sorry for explaining long and with a not so good example but I want to warn users concerned with security its based on them, no browser or software can protect you 100% it depends on your measures. Use even TAILS or WHONIX to be even more safe. That should be enough.

[Cyaren]

You can always send a message with a note attached. With that you can write messages.

You can also encrypt that message with some sort of security to make it private, because as people before me said, anyone with the txid would be able to read the message.

[sellcollateral]

Short Question:

Alice and Bob want to tranfer a secret letter. How can they transfer the information with the use of the blockchain?

Thanks!

Why the need for the blockchain?

1) just a secret message transfer:
bob publishes his public key, alice encrypts the message to that key and sends to bob.

2) a secret message transfer with some deniability for both:
as in (1) except alice transfers encrypted message to a dropbox like mailinator

Use of a blockchain would be indicated if you wanted the message to remain around forever, immutable. 
Do you really need this? Possibly you only need the hash of the message to be kept immutable forever?

I personally think this is the best answer... combine this approach with a service like https://privnote.com/ and you have a pretty secure method of sending messages to eachother...