
Show HN: Unum – a cryptocurrency worth $1 - impostervt
https://unum.one
======
impostervt
I've long felt that a price-stable cryptocurrency is vital to increased
acceptance of cryptocurrency by businesses and the public at large. There are
a few solutions to this problem out there, but, in my opinion, they are either
too centralized (and require too much trust) or they're too complicated. I
wanted something simple, distributed, and trustless, so I made Unum.

[https://unum.one](https://unum.one)

Unum is implemented as an ERC20 token smart contract on the Ethereum
Blockchain. If you send in $20 worth of Ether, you get 20 Unum. If you send in
$100 worth of OMG, you get 100 Unum. Whatever you send in is held in reserve
by the smart contract. I can't touch it, and you can exchange your Unum into
any currency held in the reserve whenever you'd like. Both buying and selling
Unum incurs a 0.05% fee, which I plan to use to pay for the Ether needed to
maintain the USD price oracle contract that's used to maintain the dollar peg.
For every $100 you send, $0.05 is held as a fee.

Right now Unum is deployed on the Ethereum Ropsten testnet. I'd love feedback
on the contract itself, which is on Github, and on the website. You can buy
and sell Unum on the Ropsten network today if you have MetaMask through the
Unum website. Buying and selling is done directly on the blockchain, there is
no backend to the unum website itself. If you'd prefer, you can also use Mist
to interact with the Contract directly.

I plan to move to the main Ethereum network soon, baring any major bugs being
found.

If you're interested more in my thinking behind Unum, you can read the blog
post, below, or just ask any questions here.

[https://github.com/UnumOne/unum](https://github.com/UnumOne/unum)

[https://medium.com/unum/from-many-
unum-8c8493a8db9d](https://medium.com/unum/from-many-unum-8c8493a8db9d)

~~~
Finnucane
Price stability is a requisite for a currency that you intend to actually use
as money, but in this case it seems you have to buy some other crypto token
first in order to buy yours. That just adds to the transaction cost.

~~~
impostervt
It maintains it's price stability by using other cryptocurrencies as a
surrogate to the USD.

~~~
Finnucane
But you still have no way to buy unum directly with dollars, is that right?
It’s not useful unless you already have some other crypto coin.

------
seanwilson
> Whenever a user buys or sells Unum through the Unum Smart Contract, the
> current US dollar value of the exchanged cryptocurrency is found on another
> smart contract, called the Price Oracle. The Price Oracle is constantly
> being updated with the current average price of crypto-currencies. This
> price oracle allows Unum to maintain it's link to the US dollar.

Cool project! How do the updates work? There's a server somewhere running a
scheduled task that pulls in the prices and pushes the average. How often does
it run? What if it fails to run? Can the lag between the average price given
by the Price Oracle and the actual average be taken advantage of in terms of
making money?

~~~
impostervt
It checks for price changes every minute, and sends an update if the price
change is greater than half a percent. If if fails to run (server down) I get
an alert.

You could do arbitrate with the Unum Smart Contract the same way you could
with an exchange, but true arbitrage opportunities are rare.

------
hidiegomariani
How does it differ from tether ([https://tether.to/](https://tether.to/)) ?

