You're a bidder now. Let's run a tender.
Road resurfacing, Galle
You've been invited to bid, along with three other companies. Lowest price wins.
Over the next two minutes your price gets sealed, its key gets split, it goes into a public log you can try to forge, and it's compared against the others in private. Every step tells you if it's the real cryptography or an illustration.
Name your price
The rival bids are somewhere between 10 and 14 million rupees. Go low enough to win, but not so low you lose money.
Sealed on your phone
Your phone just encrypted your price with AES-128-GCM. This is what leaves your phone:
- Your price
- What the platform stores
- The key that opens it. Never sent as it is
I store it. I just can't read it.
Nobody holds the key
The key was cut into three shares, one for each independent custodian. Tap one custodian, then a second.
Now try to cheat
Your sealed bid is entry 4 in the public log, and its root was cosigned by two independent witnesses. Suppose you want to change your bid after the fact. Edit your entry below.
Who won?
The deadline passed. Four sealed bids are in, each one signed by "one of the invited companies". The custodians now compare them on shares, without opening any.
Don't trust us. Check.
Anyone can verify the whole tender without logging in. This is what the verifier walks through:
- The tender was signed by the company and its approver.
- Every bid is in the public log, where its receipt says.
- Both witnesses cosigned, with a trusted timestamp.
- Every bid arrived before the deadline.
- All three custodians acknowledged every bid.
- The winner came from the signed comparison, and nothing else was opened.
You ran a tender and nobody saw your price.