Is it possible to develop IoT auth system based on smart contracts? (and how it have to work) And what will be pros and cons against another systems? Could someone explain this?
Is IoT and Blockchain Possible?
Is it possible to develop IoT auth system based on smart contracts?
Yes it absolutely is.
Project Oaken is all about IoT meets the blockchain, they even have a demonstration of their platform using a Tesla: https://www.youtube.com/watch?v=lKJrTeNQGZE
See https://slock.it/ .
Slock it is another high profile example of IoT meets the blockchain.
Pros and Cons of IoT on Blockchain:
And what will be pros and cons against another systems?
I'm presuming you mean non-blockchain systems? Basically this will be the same as anything that relies on blockchain technology.
Disintermediation & trustless exchange
Two parties are able to make an exchange without the oversight or intermediation of a third party, strongly reducing or even eliminating counterparty risk.
Users are in control of all their information and transactions.
High quality data
Blockchain data is complete, consistent, timely, accurate, and widely available.
Durability, reliability, and longevity
Due to the decentralized networks, blockchain does not have a central point of failure and is better able to withstand malicious attacks.
Users can trust that transactions will be executed exactly as the protocol commands removing the need for a trusted third party.
Transparency and immutability
Changes to public blockchains are publicly viewable by all parties creating transparency, and all transactions are immutable, meaning they cannot be altered or deleted.
With all transactions being added to a single public ledger, it reduces the clutter and complications of multiple ledgers.
Interbank transactions can potentially take days for clearing and final settlement, especially outside of working hours. Blockchain transactions can reduce transaction times to minutes and are processed 24/7.
Lower transaction costs
By eliminating third party intermediaries and overhead costs for exchanging assets, blockchains have the potential to greatly reduce transaction fees.
Resolving challenges such as transaction speed, the verification process, and data limits will be crucial in making blockchain widely applicable.
Uncertain regulatory status
Because modern currencies have always been created and regulated by national governments, blockchain face a hurdle in widespread adoption by pre-existing financial institutions if its government regulation status remains unsettled.
Blockchain applications offer solutions that require significant changes to, or complete replacement of, existing systems.
Blockchain represents a complete shift to a decentralized network which requires the buy-in of its users and operators.
Blockchain offers tremendous savings in transaction costs and time but the high initial capital costs could be a deterrent.
As per Badr Bellaj's suggestion - I add as a con the privacy issue - While solutions exist, including private or permissioned blockchains and strong encryption, there are still cyber security concerns that need to be addressed before the general public will entrust their personal data to a blockchain solution.