THE POST-QUANTUM CHALLENGE
Quantum computers are making rapid progress and represent a growing threat to cryptography. Some current algorithms will become vulnerable, while others will remain safe. It's a legitimate question that Sigalion Vault users ask themselves: is my data protected against this threat?
The good news: yes, and we'll explain why.
CURRENT SITUATION: YOUR ENCRYPTION IS ALREADY POST-QUANTUM
Symmetric algorithms: Protected by default
Sigalion Vault's foundation rests on two symmetric encryption algorithms:
- AES-256-GCM (Advanced Encryption Standard with 256-bit key)
- ChaCha20-Poly1305 (with 256-bit key)
Here's a crucial point often misunderstood: symmetric algorithms are NOT vulnerable to quantum computers in the same way asymmetric algorithms are.
Even a very powerful quantum computer cannot "break" AES-256 using Grover's algorithm (the most effective known quantum approach). This algorithm only reduces security by a quadratic factor: it would require ~2^128 operations instead of 2^256, which remains astronomically impractical.
Conclusion: your current symmetric encryption is expected to remain secure for several decades, including in the face of future quantum computers, according to current knowledge.
Key derivation: Not threatened
Sigalion Vault uses two key derivation functions:
- PBKDF2 (with 1 million iterations)
- Argon2id (with memory-hard parameters of 4096 KiB)
Both algorithms rely on cryptographic hash functions, and there is currently no known relevant quantum attack against them. Your password should not be affected by the emergence of quantum computers.
THE POTENTIAL RISK: X.509 CERTIFICATES
Here's the important point to understand: Sigalion Vault does not generate its own certificates. You use third-party X.509 certificates, issued by external certification authorities.
The potential post-quantum risk lies in these certificates, as they typically rely on:
- RSA - algorithm based on factorization, vulnerable to quantum computers
- Elliptic curves (ECDSA) - algorithm based on discrete logarithm, also vulnerable
How does the vulnerability work?
Quantum computers use Shor's algorithm to factor large numbers (RSA) or solve the discrete logarithm problem (ECDSA). A sufficiently powerful quantum computer could theoretically:
- Extract the private key from an RSA/ECDSA certificate
- Forge digital signatures
- Decrypt a session key encrypted with that certificate
Experts estimate this risk could become concerning in 5 to 10 years, depending on key sizes and the evolution of quantum technology.
A threat not yet present
It's important to nuance: this risk is technically real, but sufficiently powerful quantum computers don't exist yet. Experts estimate this threat could become concerning in several years. In the meantime, certificates issued by serious certification authorities remain safe and reliable.
CONCLUSION
Sigalion Vault benefits from robust cryptographic architecture today. Faced with the foreseeable evolution of the quantum threat, the Sigalion team ensures regular technological monitoring of emerging post-quantum standards. If adaptation becomes necessary in the years to come, it will be implemented gradually and transparently.
In summary:
- Your data and files remain protected by encryption that will stay secure for many more years.
- The use of a strong password combined with proven key derivation functions is not threatened by quantum computers.
- Sigalion Vault will be adapted based on the evolution of post-quantum standards and real threats.