The whole point of using a blockchain is to let people — in particular, people who don’t trust one another — share valuable data in a secure, tamperproof way.” — MIT Technology Review

This MIT Technology Review statement is somehow tricky and can be considered as a half-truth. This is because not all blockchain systems are the same and simply using a “blockchain” does not solely guarantee that we are in the presence of a tamper-proof solution. Usually, enterprise focused blockchains come with a ‘blockchain hook’ for advertising, but in the background, they do not differ much from a traditional centralized database or any cloud service.

How is this possible? Let’s go through a few blockchain basics for some clarification and trying to keep definitions as simple as possible.



  • A blockchain is a type of database where the information is structured in blocks and saved in different computers (nodes) at the same time (decentralized).
  • It’s a type of Distributed Ledger Technology (DLT) that works with a peer-to-peer protocol connecting the different nodes.
  • Each node has the same information (with the same blocks).
  • This “decentralization” of the database (mirror copies) allows the system to be able to verify the transactions in a corrupt event, if it has been modified or attacked.
  • Most blockchains work on a consensus basis, so if the majority of the nodes have the same information, the protocol assumes that the information they contain is truthful.

How secure is a blockchain?

As we mentioned, blockchain’s truth is created by a consensus algorithm. The nodes agree what is true and what is not true. This gives as a hint that the answer will depend mostly on:

  1. how many nodes exist.

  2. who control those nodes.

Let’s imagine a situation where we create a blockchain (or use an enterprise solution available on the market) and create a network with 3 nodes. For branding and commercial purposes, it is correct to announce that we are using a blockchain solution, but the tamperproofing of our system will be (at least) arguable. At any time, the solution provider (who owns the 3 nodes) can modify that blockchain truth as he can alter consensus when required. The same occurs in companies that create consortiums or private blockchains with special permits, where if the nodes (companies) agree on modifying or excluding information, the possibility is always available. So although even this could sound attractive, no extra benefit will provide this type of blockchain solution to a centralized database  (where the owner or owners’ have control).

The real trustworthy blockchain networks are those that are made for public usage, and where the information is structured for not being altered. Public blockchains work on an incentive logic that allows value to be stored on it. The two most important blockchain networks that exist are: Bitcoin (100.000 nodes) and Ethereum (8.000 nodes); and both daily resist thousands of unsuccessful attempts of modifying the information contained in the distributed database.

Authena operation is secured on Ethereum blockchain (however, Authena framework is blockchain agnostic and easily can be adapted to any protocol as they will be developed and proven reliable and safe).

Ethereum does not only function as a currency, it permits the decentralized execution of ‘smart contracts’. For a general reference, a smart contract is probably neither smart or a contract, even the concept sounds techy an smart contract is a computer program that is saved and executed in a decentralized way (oversimplifying: each node/computer has a copy of the same computer program, eventually when we call for execution of that smart contract/program each node/computer runs it locally and simultaneously. After execution is finished in several nodes, each individual node obtains a result. Afterwards, the consensus protocol ‘EVM – Ethereum Virtual Machine’ defines that the correct ‘result’ for the execution of that smart contract is the one that the majority obtained).

Authena deployed ‘smart contracts’ allows our solution to connect directly to Ethereum mainnet and write in 8.000 computers simultaneously the evidence and life cycle of our secured products. Every interaction is timestamped and monitored in an autonomous way, creating a real digital blockchain truth that reflects what occurs in the physical world.

Selected as TOP PICK in the category blockchain at TechCrunch Disrupt Berlin 2019