{"id":185857,"date":"2026-06-23T14:42:00","date_gmt":"2026-06-23T14:42:00","guid":{"rendered":"https:\/\/mycryptomania.com\/?p=185857"},"modified":"2026-06-23T14:42:00","modified_gmt":"2026-06-23T14:42:00","slug":"why-a-blockchain-cant-be-secretly-changed","status":"publish","type":"post","link":"https:\/\/mycryptomania.com\/?p=185857","title":{"rendered":"Why a Blockchain Cant Be Secretly Changed"},"content":{"rendered":"

Banks can edit your balance. Governments can revise a record. This is the one digital ledger that even its owners cant secretly rewrite and the reason a shared global money system is even possible.<\/em><\/p>\n

Naked Market breaks down macro finance, blockchain infrastructure, AI systems, and automated trading to help readers understand the future of global finance before the mainstream catches\u00a0up.<\/p>\n

Pull up your banking app and look at the number. Your\u00a0balance.<\/p>\n

Now sit with an uncomfortable truth: that number is just a row in a database somewhere, and the bank can change it. Not should<\/em>. Can<\/em>. A few keystrokes from an admin and the row says something different.<\/p>\n

Same with the property record at your local registry. Same with a post on a platform that quietly disappears. Same with a \u201cpermanent\u201d government file that gets revised between one year and the\u00a0next.<\/p>\n

Almost every record that runs your life is editable by whoever owns the database. Thats the default state of digital information. It can be changed, and usually youd never\u00a0know.<\/p>\n

There is one exception. One kind of record where even the people who built it, who run it, who profit from it, cannot secretly go back and rewrite what already happened. And the entire idea of money moving onto shared global rails<\/a>\u200a\u2014\u200aone planet slowly agreeing on one set of pipes depends on that single strange property.<\/p>\n

Lets pull it\u00a0apart.<\/p>\n

First, kill two lazy\u00a0words<\/h3>\n

Most people file blockchain under \u201csecure because its encrypted\u201d or \u201csafe because its decentralized.\u201d Both phrases are basically noise. Theyre the kind of words you nod at without really understanding.<\/p>\n

Heres the actual thing. A blockchain isnt hard to change because of some magic password. Its hard to change because of how its built and because changing it secretly is both instantly visible<\/strong> and stupidly expensive<\/strong>.<\/p>\n

Not impossible. Visible, and expensive. Keep those two words, they do all the\u00a0work.<\/p>\n

To see why, you only need three moving parts. Most explainers drown you in jargon (we built one of these from the inside in an earlier issue<\/a>). Here, we are just going to use a notebook.<\/p>\n

Part one: every page gets a fingerprint<\/h3>\n

Theres a piece of math called a hash function. Feed it anything\u200a\u2014\u200aa word, a paragraph, an entire ledger of transactions and it spits out a short string of characters. Bitcoin uses one called SHA-256 that always returns 64 characters, no matter how much you put\u00a0in.<\/p>\n

Two things make it useful. Same input always gives the exact same output. And the output looks random, so you cant work backwards from it to the\u00a0input.<\/p>\n

Think of it as a fingerprint for data. Change the data even slightly, and the fingerprint changes. And not a little. Completely.<\/p>\n

Type \u201chello\u201d and you get one fingerprint. Type \u201chellp\u201d one letter off and you get a totally different one. Not similar. Unrecognisable. So you cannot make a small quiet edit to data without the fingerprint screaming about it. Thats lock number\u00a0one.<\/p>\n

Part two: every page carries the page before\u00a0it<\/h3>\n

Picture the notebook again. Transactions get grouped into pages, in this world we call them blocks. Heres the clever bit: every block stores the fingerprint of the block right before\u00a0it.<\/p>\n

So block 100 contains, written inside it, the fingerprint of block 99. Block 101 contains the fingerprint of block 100. On and on. Each page stapled to the last one not with glue, but with math. That staple is why its called a\u00a0chain<\/em>.<\/p>\n

Say you want to quietly change one transaction in block 100. Maybe erase a payment you made. The second you touch it, block 100s fingerprint changes (remember the avalanche). But block 101 is still carrying the OLD fingerprint. They dont match anymore. The chain is broken, right there, in the\u00a0open.<\/p>\n

To cover your tracks, youd have to redo block 101 so it points at your new fingerprint. But that changes 101s own fingerprint, which breaks 102. So you redo 102. Which breaks 103. Youre now rewriting every single block from your edit all the way to the present, pull one thread and you have to re-knit the whole\u00a0sweater.<\/p>\n

On a small notebook, annoying but doable. Which brings us to the part that actually\u00a0matters.<\/p>\n

Part three: there isnt one notebook. There are thousands<\/h3>\n

A blockchain isnt stored in one place. Thousands of independent computers around the world called nodes, each hold a full copy of the entire history<\/a>, and constantly check each others\u00a0copies.<\/p>\n

So now your secret edit has a real problem. Its not enough to re-knit your own copy. Youd have to force your rewritten version onto a majority of those thousands of machines, faster than the rest of them are adding fresh blocks, and keep doing it forever so your fake version stays\u00a0ahead.<\/p>\n

This is the famous \u201c51% attack.\u201d To rewrite history you essentially have to out-run the entire honest network combined not for a moment, but permanently. The rest of the world keeps stapling new pages. You have to staple yours faster than all of them put together, or your version falls behind and gets\u00a0ignored.<\/p>\n

How expensive is permanently out-running everyone? For Bitcoin, comically expensive.<\/p>\n

Bitcoins network now runs at somewhere around 950 to 990 exahashes per second\u200a\u2014\u200aa quantity of computing power with no useful real-world comparison. One 2025 estimate from a Duke finance professor put the cost of dominating the network for a single week at roughly $6 billion in hardware, data centres and electricity. Other estimates put a one-hour attack in the billions\u00a0too.<\/p>\n

And heres the punchline: the moment people saw it happening, the price of the thing youre attacking would collapse so youd be spending billions to steal an asset you are simultaneously destroying. The math doesnt just say \u201chard.\u201d It says \u201cwhy would\u00a0you.\u201d<\/p>\n

The other lock: skin in the\u00a0game<\/h3>\n

There is a second way to secure a chain that doesnt burn electricity, and its worth knowing because a lot of the system is heading\u00a0there.<\/p>\n

Instead of proving you did expensive work, you put money on the line. This is proof of stake the model Ethereum switched to. Validators lock up funds for the right to confirm blocks. Try to confirm two conflicting versions of history, and the network does something brutal: it destroys part of your locked-up stake and kicks you out. They call it slashing. If lots of validators try it together, the penalty scales up\u200a\u2014\u200aa coordinated attack can wipe out the entire\u00a0deposit.<\/p>\n

The system is designed so honesty is the cheapest move and cheating sets your own money on\u00a0fire.<\/p>\n

As Ethereums own documentation puts it, the incentives pay for honesty and punish bad actors. You dont have to trust that validators are good people. You only have to trust that they dont want to torch their own\u00a0capital.<\/p>\n

Now the part the cheerleaders skip<\/h3>\n

\u201cCant be changed\u201d is really \u201ctoo expensive and too visible to be worth changing\u201d and that protection is only as strong as the network behind\u00a0it.<\/p>\n

Small chains get rewritten. It happens. In September 2025, Monero\u200a\u2014\u200aa large, well-known privacy coin suffered its deepest rewrite ever. A mining pool called Qubic quietly gathered more than half the networks power, built a longer chain in private, then released it. The network, following its own rule that the longest chain wins, swallowed it. Eighteen blocks of history rolled back. Around 118 confirmed transactions briefly un-happened.<\/p>\n

No funds were ultimately stolen, but the lesson landed: when a networks cost-to-attack gets cheap enough to rent, immutability goes soft. Bitcoin Gold, Ethereum Classic, Vertcoin same story in earlier years. Security isnt a switch you flip on. Its bought, continuously, with the cost of attacking you. Which is exactly why size and decentralisation arent vanity metrics. Theyre the budget that keeps the past\u00a0frozen.<\/p>\n

And what about the thing everyone keeps bringing up\u200a\u2014\u200aquantum computers?<\/p>\n

Heres the nuance the headlines mangle. The looming quantum threat is mostly aimed at ownership<\/strong>, not at immutability. A powerful enough quantum machine could one day crack the signatures that prove a wallet is yours\u200a\u2014\u200aletting someone forge your key and move your coins. Thats serious. As of 2026 the industry estimates a rough three-to-five-year window to migrate to \u201cpost-quantum\u201d cryptography, and standards bodies have already published the replacement algorithms.<\/p>\n

But rewriting the ledger itself? One academic estimate reckoned attacking Bitcoins mining with a quantum computer would need the energy output of a star. The chains memory stays hard. Whats fragile is the lock on your front door, not the record of who lives there. Two different problems worth never confusing again.<\/p>\n

The takeaway: the Tamper\u00a0Test<\/h3>\n

So here is the tool to walk away with. Next time anyone with a coin, a \u201cblockchain\u201d startup, a government pilot, a tokenised-asset pitch tells you their records cant be tampered with, run them through three questions.<\/p>\n

Is it linked?<\/strong> Does changing the past break the present, the way a broken fingerprint breaks the chain or is it just a normal database with marketing on top? If you can edit row 4,000 and nothing else notices, its not immutable. Its a spreadsheet.Is it copied?<\/strong> How many independent parties hold a full copy and check each other? One companys private \u201cblockchain\u201d that only they can see is just their database wearing a costume. Real tamper-resistance needs many\u00a0eyes.Is it costly to cheat?<\/strong> What would it actually cost to rewrite history and would everyone see it happen? If the answer is \u201ca weekend and a rented server,\u201d treat its permanence as a suggestion, not a guarantee.<\/p>\n

Linked, copied, costly. Three questions. Most things claiming to be \u201con the blockchain\u201d fail at least one and now you can tell\u00a0which.<\/p>\n

Why any of this\u00a0matters<\/h3>\n

Step back and the bigger picture clicks into\u00a0place.<\/p>\n

For money to move onto shared global rails\u200a\u2014\u200afor 8 billion people and 180-odd governments to ever touch the same financial record, you need a record that no single one of them can secretly edit when it suits them. Not the most powerful nation that decade. Not the biggest bank. Not whoever happens to control the\u00a0servers.<\/p>\n

The whole reason a borderless money system is even thinkable is that immutability lets strangers who dont trust each other share one ledger anyway. Youre not trusting the people. Youre trusting the math, and the cost of breaking\u00a0it.<\/p>\n

Thats the quiet foundation under the One Earth, One Currency<\/a> idea this newsletter keeps circling back to. Not a coin. Not a logo. A property: a shared book of record that the powerful cant rewrite in the dark. Everything else stablecoins, tokenised treasuries, digital currencies, AI agents that settle their own payments is built on top of that one\u00a0floor.<\/p>\n

Get the floor, and the rest of the building stops looking like hype and starts looking like plumbing.<\/p>\n

Signal over noise. Structure over\u00a0price.<\/h3>\n

If you want to understand the architecture of where global money is heading before it becomes obvious\u200a\u2014\u200asubscribe. One clear breakdown at a\u00a0time.<\/em><\/p>\n

Subscribe free<\/strong><\/a><\/p>\n

Keep going<\/h4>\n

One Planet, 180 Currencies: Somethings Broken<\/strong><\/a> <\/strong>Start here\u200a\u2014\u200athe whole thesis in one\u00a0read.How Blockchain Actually Works, From the Inside<\/strong><\/a>We build a chain piece by\u00a0piece.What Is a Blockchain Ledger, Really?<\/strong><\/a>The shared book of record, and who controls\u00a0it.The New Rails: Blockchain as Infrastructure<\/strong><\/a>Why money is quietly re-plumbing onto shared\u00a0pipes.<\/p>\n

-More Soon<\/p>\n

Why a Blockchain Cant Be Secretly Changed<\/a> was originally published in Coinmonks<\/a> on Medium, where people are continuing the conversation by highlighting and responding to this story.<\/p>","protected":false},"excerpt":{"rendered":"

Banks can edit your balance. Governments can revise a record. This is the one digital ledger that even its owners cant secretly rewrite and the reason a shared global money system is even possible. Naked Market breaks down macro finance, blockchain infrastructure, AI systems, and automated trading to help readers understand the future of global […]<\/p>\n","protected":false},"author":0,"featured_media":185858,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-185857","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-interesting"],"_links":{"self":[{"href":"https:\/\/mycryptomania.com\/index.php?rest_route=\/wp\/v2\/posts\/185857"}],"collection":[{"href":"https:\/\/mycryptomania.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mycryptomania.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/mycryptomania.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=185857"}],"version-history":[{"count":0,"href":"https:\/\/mycryptomania.com\/index.php?rest_route=\/wp\/v2\/posts\/185857\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/mycryptomania.com\/index.php?rest_route=\/wp\/v2\/media\/185858"}],"wp:attachment":[{"href":"https:\/\/mycryptomania.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=185857"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mycryptomania.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=185857"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mycryptomania.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=185857"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}