Spam Invalid Transaction as Free Message Delivery?

[arthurdent6]

What happens when someone intentionally broadcasts an invalid transaction - a transaction from a wallet that has insufficient balance, for example. Does the intended recipient see the transaction, even though it's invalid? If there is a message attached to the transaction, does the intended recipient see the message?

In other words, can the bitcoin network be used to send nearly untraceable, possibly encrypted messages, for free?

[t3a]

If you send an invalid transaction to all your peers, they will see that it's invalid and no forward it to all their peers. The only way your recipient would see it is if he/she was one of your peers.

Edit: I should mention that there is a project that uses a network with the same network topology as Bitcoin to broadcast messages called Bitmessage.

https://bitmessage.org