This needs more explanation of what's going on and what the benefit is. Don't tell us it's big deal ("the holy grail of secure computation"), show us why it is.
I had to stare at the animated gif for a quite a long while before I realized the two spreadsheets were different, and I still don't get quite what's happening here. Computations are not automatically updated when input data changes like they usually are in spreadsheets? Do both sides have to agree to compute the cell before the operation is performed?
There's a succint description of the steps at the webpage:
1- Both parties have to agree to the same formulas that will be computed
2- The spreadsheets are different because the inputs of the two parties are different, not the formulas
3- When both parties agree to compute the same cell, the secure multi-party computation between both parties starts: when it's finished, the result is displayed on a destination cell or as a comment
The point is that computer users, not knowing advanced cryptography, will be able to securely compute in a transparent way (ie. "cryptography dissappears").
1. Two complex spreadsheets, they look similar (therefore, assume they're the same)
2. Click some cells
3. Wait...
4. TADA, A number appears!?!??
What is this number? How is this different from regular spreadsheets, is it just a super slow formula eval? Why are there two identical sheets (it's moving way too fast to notice that they're different)? Why did you select the cell first? Before any of these questions could be answered by actually reading the spreadsheet the animation jumps straight to the next one, which is essentially the exact same as the last with a different title at the top.
Also, why are you demoing starting from selecting the output cells, like 5 times? That's the most boring and repetitive part of your whole product.
Your demo should be MUCH simpler. Start with a single blank spreadsheet and solve the millionaire problem (you mentioned it elsewhere) in 15 seconds, including typing the formula and sending the sheet to the second person. This problem is simple to conceptualize and easy to motivate.
> There's a succint description of the steps at the webpage:
You put a colon there as if what's below is the "succinct explanation," but that explanation is no where on the site.
Also useful would be a better use-case for both parties needing to keep their numbers secret. Perhaps this is a common scenario, but I don't understand why (although I can't imagine it's that common if there's no tool yet).
One of your examples (Leveraged Buyout Analysis) shows the two views, one of which is the bank's view. In the bank's view, their premiums and fees are hidden. Why would this be secret information?
I had to stare at the animated gif for a quite a long while before I realized the two spreadsheets were different, and I still don't get quite what's happening here. Computations are not automatically updated when input data changes like they usually are in spreadsheets? Do both sides have to agree to compute the cell before the operation is performed?