Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [smart-lock]

A smart-lock is an embedded device that provides physical security to an asset. It locks/unlocks itself based on instructions received from a recognised smart contract running on a blockchain.

1
vote
1answer
29 views

Solidity: Smart Contract, always get wrong result

I'm writing a token locker contract, code as following: pragma solidity ^0.4.24; import "./SafeMath.sol"; import "./ERC20.sol"; contract TokenLocker { using SafeMath for uint256; address ...
0
votes
1answer
27 views

Time-locked deposit protocol?

I am designing a protocol where a user A sends a time-locked deposit to user that if the user B within time t provide a proof that he exists in a location x (this may be obtained by third party like ...
1
vote
2answers
286 views

Slackness issue and time in smart contracts

At a high level, slackness issue says, it is not possible to guarantee that at any given point in time all honest miners see exactly the same blockchain length [1]. On the other hand, as we know the ...
6
votes
2answers
938 views

Smart contract erc20 code snippet to prevent buyer token transfers

I´m going to start a token pre-sale and I want to be able to send the tokens to the buyer but prevent the buyer to send tokens to another wallet. I tried the following in my ERC20 smart contract but ...
0
votes
1answer
144 views

How can smart lock inform Contract that it has been locked?

Suppose Smart lock (SL) has an Internet connection. How can SL send message to Smart Contract when User close SL? How to protect from reply attack? Is there any gas effective way to check SL ...
8
votes
3answers
639 views

How do smart locks make sure that they have access to an up-to-date version of the blockchain?

Smart locks like Slock.it are supposed to allow locks to be able to do things based on the blockchain state. Does that work with locks that don't have their own internet connection? If so, how does ...