Bitcoin Forum

Bitcoin => Bitcoin Discussion => Topic started by: str4wm4n on March 10, 2013, 06:13:15 AM



Title: Can BTC be used as a GNUPG replacement?
Post by: str4wm4n on March 10, 2013, 06:13:15 AM
I probably don't know/understand enough about the inner workings of both bitcoin and pgp, so please forgive me if the answer to my question is obvious!

is it possible to encrypt a message using a bitcoin address and then decrypt it using the private key of that address?

if someone wants to send me a private message, and they know a bitcoin address of mine, can they use it for encryption, and can I decrypt the message with my private key?



Title: Re: Can BTC be used as a GNUPG replacement?
Post by: misterbigg on March 10, 2013, 06:33:25 AM
Short answer: Yes

Long answer: Someone needs to write the software to allow out-of-band encryption and decryption of messages using Bitcoin public/private key pairs.

Edit: Well, armory beat me to it!


Title: Re: Can BTC be used as a GNUPG replacement?
Post by: cypherdoc on March 10, 2013, 07:13:45 AM
Isn't this the bitmessage method?


Title: Re: Can BTC be used as a GNUPG replacement?
Post by: Stardust on March 10, 2013, 01:22:21 PM
GPG is an identity mechanism, and is tied to your email. Bitcoin addresses are all anonymous, and aren't really easy to pin point to a straight forward id.

You don't email to use GPG, and you can be anonymous.  Technically both Bitcoin and GPG are pseudonymous.

It would be cool if GPG would implement some things from Bitcoin:  Instead of hex, encode the hash (fingerprint) into Base58/62.  Support for ECDSA/ECDH (or something similar to go with ECDSA).  Include public key in signature.


Title: Re: Can BTC be used as a GNUPG replacement?
Post by: Killdozer on March 10, 2013, 01:42:22 PM
Quote
is it possible to encrypt a message using a bitcoin address and then decrypt it using the private key of that address?

if someone wants to send me a private message, and they know a bitcoin address of mine, can they use it for encryption, and can I decrypt the message with my private key?

Why would you want to? It's not like GPG keys cost money...


Title: Re: Can BTC be used as a GNUPG replacement?
Post by: misterbigg on March 10, 2013, 03:52:55 PM
Why would you want to? It's not like GPG keys cost money...

It's convenient if you've already established identities with someone by doing business with Bitcoin since you have each others' public keys.


Title: Re: Can BTC be used as a GNUPG replacement?
Post by: Rothgar on March 10, 2013, 03:58:48 PM
The armory page doesn't claim that messages can be encrypted.  It only claims that messages can be signed.


Title: Re: Can BTC be used as a GNUPG replacement?
Post by: wareen on March 10, 2013, 03:59:37 PM
is it possible to encrypt a message using a bitcoin address and then decrypt it using the private key of that address?

The problem here is that Bitcoin addresses are hashes of public keys and not public keys themselves. As soon as the owner of the address broadcasts a transaction however, the full public key becomes part of the blockchain. You might be interested in Bitmessage for a full-blown solution to that problem but then again: GPG works just fine.


Title: Re: Can BTC be used as a GNUPG replacement?
Post by: gyverlb on March 10, 2013, 04:06:45 PM
GPG manages a web of trusts which can be mandatory when you can't meet a person yourself to verify his/her identity and have to rely on people you trust to do it.