Why is a Smart Contract secure?

Since Vitalik Buterin developed Ethereum, smart contracts have become an integral part of the blockchain ecosystem. But what is behind these „smart contracts“? In five parts, Ingo Rammer explores the implications of the technology for us. Today: Why is a Smart Contract secure?

Why exactly is the Bitcoin evolution safe?

So far, so good. But what about the security of this approach? What would happen if one of the participants simply exchanged the smart contract on the blockchain node he controlled and used a variant that was advantageous for him like this https://www.onlinebetrug.net/en/bitcoin-evolution/? (Depending on the blockchain, the attacker would have to dive relatively far into the internals of the implementation of the blockchain platform – but it is still a valid attack vector that has to be considered at least on a theoretical level).

What would an attacker have to do?

In our example, an attacker could try to take control of all phone numbers by changing the check conditions in his version of the smart contract. But this would lead to the World State being changed only on the attacker’s node: Only for him it looks as if he controls all telephone numbers.

All other participants would continue to execute the correct version of the contract. If, due to the consensus mechanism chosen between the participants, the attacker is selected by the network itself to generate new blocks, these would immediately be rejected by the other participants.

The attacker would lose the status of the block generator again, since depending on the configuration of the block chain, half or two thirds of all participants must agree with the result of a transaction before it is considered correct network-wide. An attack attempt therefore only harms the attacker himself.

One can therefore compare this attack with a bank customer crossing out the status on his printed account statement and overwriting an increased credit balance. From his point of view, he now has much more money than before. But as soon as he tries to access this money, he is very quickly brought back to the bottom of the facts: his own view remains a wish and will at best be acknowledged by his counterpart with a smile.

Blockchain technology in the healthcare of the future

As in all other industries, blockchain technology does not stop at the healthcare sector. Even though many ideas are still being discussed in this market, it is already clear that the possibilities of the new technology seem to have great potential in many respects.

Looking at current surveys, decision-makers in the health care sector have a positive long-term view of this development. But where can Blockchain be used in healthcare at all?

The use of blockchain technology in healthcare can cover very different areas

In the pharmaceutical industry to prevent the production of counterfeit medicines, in hospitals in hospital logistics for example to track supply chains and demand-oriented stock levels and quality assurance.

Blockchain can be used for early warning systems and can transfer data from wearables. Autonomous monitoring of durable medical devices, such as a pacemaker: Blockchain technology can also be used for this purpose efficiently and reliably.

However, the particular field of application will be in the networking of the health care system. Blockchain technology opens up the possibility of cryptographically securing and updating patient data and handing it over to patients.

The advantages of blockchain technology

The advantages of the system lie above all in the security of the technology. An issue that is becoming increasingly relevant, especially in times of hacker attacks. If the data is currently stored on servers of doctors or health insurance companies, it can be saved as a valid information block on the blockchain in the future.

Another important point is the optimization of processes, which leads to a saving of time and money. This is currently an enormous advantage of the technology, especially in view of the increased expenditure in the healthcare system.

The probably decisive advantage for consumers is the „democratization of data“. With blockchain technology, data can lie in the patient’s hands and be used in a self-determined way. Everyone would have their own influence on the flows of their data and could decide for themselves which data is made available to whom and how it is used.

It would then remain for the user to decide whether he wants to make data available to his doctor or possibly to a pharmaceutical company for research purposes.

What are the challenges, limits and future hurdles?
The possibilities in the healthcare sector in particular seem to be groundbreaking and bring new dynamics into an established system. Nevertheless, the players are complaining that it is currently difficult to estimate the relationship between benefits and costs. Necessary investments are difficult to quantify and the return on investment is also difficult to estimate – a risk.

Legal questions also arise. Who is responsible for the data and where are the responsibilities? There are also ethical questions that need to be discussed: Incorrect incentives to transmit data for research purposes can have the opposite effect.