Introduction
Hi all. I'm the developer of http://www.proofofexistence.com/, and a collaborator in the chromawallet colored coin wallet project (http://chromawallet.com/). I'm quite new to altcoins but have some experience developing bitcoin-related apps.

I don't usually read or post in this subforum, but I had an idea for an alt-coin and I wanted to see what's the public reception for it. If it seems useful, I'll create it and release it. In fact, I already started working on it, but decided to make this post before continuing, to get some feedback.


Sheercoin, the minimalist cryptocurrency

The idea behind sheercoin is to create a cryptocurrency with as little overhead as possible. My plan is to start with bitcoin and remove everything that's not strictly necessary for a cryptocurrency to work. This means:

• No coinbase messages
• No multisig transactions
• No P2SH
• No OP_RETURN
• No scripting at all, in fact
• etc. Open to suggestions on what to "trim"

Double-signed transactions concept
I'd also want to throw an idea, which may or may not be suitable for sheercoin: what if the protocol required all transactions to be signed by both the sender and the receiver of coins?

For example, say Alice wants to send 1 coin to Bob. In bitcoin, Bob doesn't need to do anything for this to happen. Alice just needs to broadcast a signed transaction in which she proves she owns some unspent outputs, point them to Bob's address, and voilà: Bob now has the right to those bitcoins.

In sheercoin, we could make it so that both Alice AND Bob need to sign the transaction for it to be valid. This would require a little bit of extra effort for the users, as the transaction signed by Alice must be sent to Bob for signing before being broadcasted to the network. I think this would make it impossible to send sheercoins to non-existent private keys (like https://blockchain.info/address/1BitcoinEaterAddressDontSendf59kuE or the addresses generated by http://www.proofofexistence.com/)

The goal is to create the most bare-bones cryptocurrency implementation possible, plus double-signing of transactions. This will hopefully be useful to many people that want to use a blockchain-based cryptocurrency which doesn't allow other uses like document time-stamping or data embedding. Is there any other known good practice we should follow for creating a new altcoin?

Timeline
Depending on feedback, the plan is to release sheercoin early next year.

Thoughts?
Happy 2014!
Manuel