is it currently possible in the Bitcoin blockchain to send coins to an address only after two parties sign messages signaling the funds to be released Like the question states, is it currently possible in the Bitcoin blockchain to send coins to an address, but have the transaction written into a block or validated only after two parties sign messages into the blockchain that the funds should be released?

If it does exist, how does this technically work? 

A comment describing or linking to something similar to this or on the off-chain level would be appreciated too.
It's a built-in blockchain feature called a multisig transaction. 

https://en.bitcoin.it/wiki/BIP_0010