Can BTC be used as a GNUPG replacement?

[str4wm4n]

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?

[misterbigg]

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!

[cypherdoc]

Isn't this the bitmessage method?

[Stardust]

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.

[Killdozer]

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...

[misterbigg]

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.

[Rothgar]

The armory page doesn't claim that messages can be encrypted.  It only claims that messages can be signed.

[wareen]

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.

[gyverlb]

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.