Blockchains are an titillating fresh development, but the satan is ter the detail
Much of what you’ve heard about the blockchain revolution is nothing but snake oil and marketing spin. This fresh technology has bot touted spil the cure-all for performing secure and trusted transactions. The mere mention of the word blockchain sends fintech and banking execs into madness.
Australia Postbode even threw its hat into the blockchain stadionring te early 2016 when it exposed it intended to use blockchains to store identities. Australia postbode also recently made a subordination to a Victorian government committee conducting an inquiry into electronic voting. The obedience suggested that it could use ‘blockchain’ technology, but provided no detail on how or why a blockchain would improve the electronic voting process. The finance and banking sector is also investing te the technology.
The entire blockchain phenomenon began with the success of Bitcoin – a type of digital ‘cash’ that uses various cryptographic processes to secure transactions inbetween untrusted third parties, without the need for a central authority or canap.
While the blockchain is indeed a critical part of the Bitcoin security specimen, it is no silver bullet. The hype surrounding the blockchain buzzword greatly exaggerates what blockchains are, and totally neglects the ingewikkeld interplay of many critical technology components that work together to make Bitcoin secure.
So, what is the blockchain?
The blockchain is a distributed ledger book of all Bitcoin transactions. This means there’s no single database of records. The distributed nature of the blockchain also helps to secure it because the Bitcoin community collectively agree on all transactions, there’s no central authority that can block or switch roles payments.
Imagine it spil a physical book where each pagina contains about ten minutes of Bitcoin transactions. After Ten minutes of transactions, the pagina is stamped with a special serial number (a hash), and glued permanently into the ledger book.
Everyone can be assured that the transaction list ter the ledger book is secure and accomplish because nobody can insert, modify or delete a transaction without tearing out the pagina. The serial number hash makes this process very difficult because it ensures all pages are mathematically ‘locked’ (or chained) together. If any content on a previous pagina is modified, the serial numbers will no longer align, and everyone would know that something hinky is going on.
The only way to alter a transaction ter the blockchain book is to rip out the pagina containing the transaction, plus all the following pages. Then alter the transaction on the original pagina, and then re-print every subsequent pagina, creating a fresh hash, and then gluing all of those pages back into the book. Bitcoin transactions are secure because it’s just too much work to modify them!
Buying a pizza with a blockchain
If I’m spending $Ten at Lizza’s Pizzas, I can ‘broadcast’ a message to all Bitcoin users, requesting that they make a note of my transaction te the current block. Because the blockchain is open for inspection, Lizza can see the blockchain until she sees my payment recorded. Furthermore, because the blockchain is secure against tampering, Lizza can be certain that the transaction is finish – there’s no way I could scam hier and steal $Ten worth of pizza.
If someone were to examine the blockchain after my transaction with Lizza, they’d see that hier account had $Ten te it that came from my account. When Lizza wants to spend $Four.50 on a tijdschrift from Nate’s News, Nate inspects the blockchain to confirm that Lizza has enough money ter the account to voorkant the $Four.50 transaction, and then witnesses for Lizza’s transaction ter the blockchain.
The blockchain ledger book verifies the money ter Nate’s account through the linkage from Nate to Lizza to mij (and so on). This is how all transactions are chained together, every transaction is linked to all previous transactions through the history of blocks te the blockchain.
Blockchain protecting transactions
While I wouldn’t bother attempting to skip out on a $Ten pizza, if I could lightly switch roles a million dollar sale I might think about it.
Baked ter security
A ordinary blockchain is nothing more than a list of transactions that is chained or linked together using novel gegevens structures, and some basic cryptographic principles. Anyone can make a blockchain, and create blocks. My little old laptop can make millions of blocks every 2nd, they just wouldn’t be secure like Bitcoin’s blocks.
This is where the subtly inbetween blockchains and security is lost. Bitcoin isn’t secure because of blockchain, it is secure because the effort and cost of subverting its blockchain is greater than the value of what’s being protected. The effort and cost that protect Bitcoin comes ter the form of time, computing power and electro-stimulation.
The effort is dictated by the rules that are ‘baked in’ to what Bitcoin is. The rules provide mathematical certainty from how transactions are ‘signed’ through to how much ‘proof of work’ needs to accompany a block.
There are many parts to the Bitcoin rulebook, and each and every part is essential to the scheme’s overall security, no single factor (including the blockchain) is enough to secure Bitcoin transactions.
Mining blocks is expensive work
The miners make blocks by gathering end-user transactions (my $Ten pizza order for example), combining them and calculating hashes. When they detect blocks that match Bitcoin’s rules they add the block to the chain, and collect a prize.
Unlike our paper-ledger-book example, the difficulty te creating a single block is immense. It (presently) takes the collective efforts of many thousands of miners testing 1.6-million-million-million hashes vanaf 2nd to detect one ‘block’ every Ten minutes, they’re working at a speed that’s omschrijving to 130-billion ‘average’ desktop computers working ter parallel. Thesis mining computers are real devices, taking up real physical space, and they collectively consume gigawatts of real power.
Economics and mathematics — blockchain armor
Even if an attacker managed to corset gigawatts of computing power (or subvert half of the thousands of miners working to create Bitcoin blocks), the attacker would still only have a marginal advantage. The theoretical ‘51 vanaf cent attack’ against the Bitcoin network improves the probability of controlling the ‘next’ block. But, using such an attack to re-write history (many blocks) is still almost unlikely.
It’s the rules that govern the integrity of a bitcoin block that secure the blockchain. The rules ensure that the computing power required to rip out a latest block, alter a transaction, then re-create all subsequent blocks is more than any attacker and even most governments could amass.
The Bitcoin blockchain is protected by the massive group mining effort. It’s unlikely that any private blockchain will attempt to protect records using gigawatts of computing power — it’s time consuming and expensive. Within a private blockchain there is also no ‘race’, there’s no incentive to use more power or detect blocks swifter than competitors. This means that many in-house blockchain solutions will be nothing more than cumbersome databases.
There is also no need for a ‘51 vanaf cent’ attack on a private blockchain, spil the private blockchain (most likely) already controls 100 vanaf cent of all block creation resources. If you could attack or harm the blockchain creation instruments on a private corporate server, you could effectively control 100 vanaf cent of their network and alter transactions however you wished.
Sure, blockchains are an titillating fresh development, but the demon is te the detail. Without a clear security prototype, proprietary blockchains should be eyed with suspicion.
Nikolai Hampton holds a Master’s Degree ter Cyber Security and is a director of Impression Research. He consults on matters of privacy, security, digital forensics, and incident response. His concentrate is on the keurig application of cryptography. He is sultry about educating business on elaborate security issues. Go after Nikolai on Twitter: @NikolaiHampton