Bitcoin is considered secure today because it relies on complex cryptographic algorithms. However, with the rise of quantum computing, its security might be at risk. Let’s understand how and why this can potentially devalue Bitcoin.
🔐 Bitcoin's Current Security
Bitcoin uses:
SHA-256 for mining (to secure blocks)
ECDSA (Elliptic Curve Digital Signature Algorithm) to secure wallets and transactions
These are strong against classical computers, but quantum computers could break them.
⚛️ What Quantum Computers Can Do
Quantum computers can solve problems millions of times faster than regular computers.
Here are two quantum algorithms that pose threats:
1. Shor’s Algorithm
Breaks public key cryptography (like ECDSA)
Can reveal private keys from public keys
2. Grover’s Algorithm
Speeds up the process of finding a hash collision (used in SHA-256)
Cuts Bitcoin mining security in half
🧮 Numerical Example
Let’s take real-world numbers to see the impact:
✅ ECDSA Key Breaking (Private Key Exposure)
Classical computer: Would take 10⁷⁰ years to break a Bitcoin private key.
Quantum computer (with ~4000 qubits): Could do it in 10 minutes using Shor’s Algorithm.
🔍 What does this mean?
If someone sends Bitcoin and the public key becomes visible, a quantum hacker could steal it before the transaction is confirmed.
⛏️ SHA-256 Mining Impact
Currently, it takes about 2²⁵⁶ operations to guess a Bitcoin block hash.
With Grover’s Algorithm, it would take about 2¹²⁸ operations.
🧠 Result: Mining becomes easier for quantum computers, giving unfair advantage and risking network centralization.
💣 How This Can Devalue Bitcoin
1. Loss of Trust
If users know their wallets can be hacked, they’ll stop using Bitcoin.
2. Network Attack Risk
Hackers with quantum computers could:
Steal coins from old addresses
Perform double-spending
Control 51% of the network with fewer resource
3. Price Drop Scenario
Let’s imagine:
Bitcoin is at $50,000
A quantum attack is detected
Market panic causes a 30% crash in a day
Price drops to $35,000 or lower
🛡️ Can Bitcoin Protect Itself?
Yes, with quantum-resistant cryptography:
Post-quantum algorithms like Lattice-based cryptography can replace current ones.
Bitcoin developers may upgrade the protocol in future.
✅ Conclusion
Quantum computing is still developing, but it has the potential to devalue Bitcoin by:
Breaking its core security
Creating unfair mining advantages
Damaging user trust
🚨 Bitcoin is not doomed, but it must evolve before quantum computers become powerful enough.