For now, probably: Quantum computers can't break ECDSA yet You have time to migrate Watch for quantum computing advances Recommendation: Don't panic, but plan for migration.

The Quantum Threat

Q: Quantum computers are decades away, why worry now?

Harvest now, decrypt later: Data recorded today can be decrypted later Migration takes time: Moving entire ecosystems is slow Better safe than sorry: Cryptographic agility is valuable

Q: Can't Bitcoin just upgrade?

Yes, but it's complicated: Consensus required: Hard fork needs community agreement Address migration: Users must move funds manually Lost coins: Funds in lost wallets remain vulnerable BTQ demonstrates this upgrade is possible.

Q: What if Dilithium is broken?

Unlikely: Based on 30+ years of lattice research NIST vetted: 7-year standardization process Upgradeable: BTQ can adopt new algorithms if needed Defense in depth: Hybrid signatures possible

Quantum computers pose an existential threat to the cryptography that secures most cryptocurrencies. This page explains the threat and why BTQ provides protection.

What Are Quantum Computers?

Quantum computers use quantum mechanical phenomena to perform calculations:

Qubits: Unlike classical bits (0 or 1), qubits can be both simultaneously (superposition)
Entanglement: Qubits can be correlated in ways impossible for classical bits
Interference: Quantum states can be combined to amplify correct answers

This allows quantum computers to solve certain problems exponentially faster than classical computers.

The Threat to Cryptography

Shor's Algorithm

In 1994, mathematician Peter Shor discovered a quantum algorithm that can:

Factor large numbers in polynomial time
Solve discrete logarithms in polynomial time

This breaks:

RSA: Based on factoring difficulty
ECDSA: Based on discrete log difficulty (used by Bitcoin and most cryptocurrencies)
Diffie-Hellman: Used for key exchange

Shor's algorithm doesn't just make these problems "a bit easier" - it reduces the difficulty from billions of years to hours or minutes.

What This Means for Bitcoin/ECDSA

ECDSA security relies on the hardness of the Elliptic Curve Discrete Logarithm Problem (ECDLP):

Given: Public Key P = k * G (where G is the generator point)
Find:  Private Key k

Classical computers: Would take longer than the age of the universe Quantum computers: Could solve in hours with ~2,300 logical qubits

Grover's Algorithm

Grover's algorithm provides a quadratic speedup for search problems:

Classical: O(N) operations to search N items
Quantum: O(sqrt(N)) operations

This affects:

Hash functions: Security effectively halved (256-bit becomes 128-bit)
Mining: Quantum miners would have an advantage

However, this is less severe than Shor's algorithm - doubling key sizes provides protection.

Timeline: When Will This Happen?

Current State (2024-2025)

Largest quantum computers: ~1,000+ physical qubits
Error rates: Still too high for useful cryptography attacks
Logical qubits: Very few (physical qubits needed for error correction)

Expert Estimates

Timeframe	Probability	Source
By 2030	5-10%	NIST
By 2035	15-25%	Various researchers
By 2040	50%+	Industry consensus

These are estimates for breaking RSA-2048 and ECDSA. The actual timeline is highly uncertain.

The Real Concern: Harvest Now, Decrypt Later

Even if quantum computers are years away:

Attackers record blockchain data today
When quantum computers arrive, they decrypt historical signatures
Public keys are revealed when transactions are broadcast
Funds can be stolen from addresses with exposed public keys

This means the threat is already real for long-term security.

What's at Risk in Bitcoin/Cryptocurrencies?

Exposed Public Keys

When you spend from a Bitcoin address, your public key is revealed:

Before spending: Only address (hash of public key) is known
After spending:  Full public key is on the blockchain

At risk: Any address that has ever sent a transaction (~30% of all Bitcoin)

Reused Addresses

Address reuse compounds the problem:

Public key known from first spend
Additional funds sent to same address are vulnerable

Lost Coins with Known Public Keys

Early Bitcoin transactions used pay-to-public-key (P2PK):

Public key directly in the transaction
Includes Satoshi's ~1 million BTC

How BTQ Solves This

Dilithium: Post-Quantum Signatures

BTQ replaces ECDSA with Dilithium, a lattice-based signature scheme:

Property	ECDSA	Dilithium
Security basis	Elliptic curves	Lattices
Vulnerable to Shor?	Yes	No
NIST standardized	Yes	Yes (FIPS 204)
Quantum security	0 bits	128 bits

Why Lattice Cryptography?

Lattice problems are believed hard for quantum computers:

No known quantum algorithm provides exponential speedup
Studied for decades with no efficient attacks found
NIST selected Dilithium after 7 years of evaluation

Migration Path

BTQ provides a path to quantum safety:

Generate Dilithium address: btq-cli getnewdilithiumaddress
Move funds: Transfer from ECDSA to Dilithium addresses
Future-proof: Quantum computers cannot steal from Dilithium addresses

The NIST Post-Quantum Standardization

Timeline

2016: NIST begins post-quantum cryptography competition
2017: 69 submissions received
2019: 26 advance to second round
2020: 7 finalists selected
2022: 4 algorithms selected for standardization
2024: FIPS 203, 204, 205 published

Selected Algorithms

Algorithm	Type	Use Case	BTQ?
Dilithium	Signatures	Transaction signing	Yes
Falcon	Signatures	Alternative signatures	Future
SPHINCS+	Signatures	Stateless signatures	Future
Kyber	Key exchange	Not applicable	No

BTQ chose Dilithium because:

Primary NIST recommendation
Simpler implementation than Falcon
Better side-channel resistance
Reasonable signature sizes

Comparison of Risks

Bitcoin Today

Security: ECDSA (256-bit)
Quantum: Completely broken by Shor's algorithm
Risk: Total loss of funds when quantum computers arrive

BTQ

Security: Dilithium2 (128-bit quantum)
Quantum: No known quantum attack
Risk: Protected against foreseeable quantum threats

What About Mining?

SHA-256 and Grover's Algorithm

BTQ uses SHA-256 for Proof of Work, same as Bitcoin.

Grover's algorithm could provide advantage:

Current: 256-bit security
Post-quantum: ~128-bit security (still very secure)

Why This Is Less Concerning

Still extremely difficult: 128-bit security is plenty
Hardware limitations: Quantum mining hardware doesn't exist
Economic factors: Cost of quantum computers vs. mining rewards
Upgradeable: Hash function can be changed if needed

The signature vulnerability is far more urgent than the mining vulnerability. Signatures protect your money directly; mining is about network security.