When today's encryption stops working
Quantum computers solve certain mathematical problems dramatically faster than classical computers, and those problems are exactly what today's public-key cryptography relies on.
Hidden writing
From the Greek kryptos, meaning hidden, cryptography literally translates to "hidden writing".
It is the practice of developing and using coded algorithms to protect information so that only those with permission, and the ability to decrypt it, can read it. Cryptography keeps communication confidential, proves who you are talking to and guarantees that data hasn't been altered.
Where cryptography lives in your organisation
- TLS certificates
- VPNs & SSH
- PKI & digital signatures
- Keys & HSMs
- Databases & storage encryption
- Application source code
- Libraries & protocols
- Identity & authentication
- Payment systems
- OT & IoT devices
- Supplier connections
Each of these is a cryptographic asset that needs to be known, owned and eventually migrated.
Millions of years, or hours
Much of today's cryptography relies on hard mathematical problems that a cryptographically relevant quantum computer can break.
Millions of years
The most powerful computer today would need millions of years to factor the large numbers behind RSA, or to solve the discrete logarithms behind elliptic-curve cryptography.
Hours
Shor's quantum algorithm is expected to be able to break RSA in hours, using compute that may be available soon. Symmetric encryption and hashing are weakened too, but can be protected with longer keys.
The day the locks open
Q-Day is the moment a quantum computer can break the public-key encryption that protects the internet, banking, government services and your own systems.
Nobody can say exactly when that will be. AIVD and NCSC note that experts expect it to happen between 2030 and 2040, and that a breakthrough could make it sooner.
"If hackers get your encrypted data now, then Q-Day is already here."
The attack has already started
Attackers don't need a quantum computer today. They can intercept and store encrypted data now and decrypt it later, once the technology is available. Europol warns that this makes long-lived sensitive data vulnerable today.
Intercept and store
Encrypted traffic and data are captured from networks, breaches or backups and stored at scale.
Wait for Q-Day
The data stays valuable for years: medical records, intellectual property, state secrets, financial and personal data.
Decrypt later
Once a quantum computer is available, the stored data is decrypted, long after the original breach.
Is your data already at risk?
Professor Michele Mosca's rule of thumb shows when you need to start. If the time your data must stay secret plus the time you need to migrate exceeds the time until the threat arrives, you are too late.
X + Y > Z
- X, shelf-life: the number of years the information should be protected.
- Y, migration time: the number of years needed to migrate your systems properly and safely to a quantum-safe solution.
- Z, threat timeline: the number of years before relevant threat actors can break quantum-vulnerable systems.
Post-quantum cryptography
Post-quantum cryptography (PQC), also called quantum-proof, quantum-safe or quantum-resistant cryptography, refers to cryptographic algorithms that are believed to be secure against attack by a quantum computer. They run on today's classical hardware.
Three NIST-approved algorithms, co-developed by IBM
- ML-KEM · FIPS 203
- ML-DSA · FIPS 204
- SLH-DSA · FIPS 205
ML-KEM protects key exchange and encryption. ML-DSA and SLH-DSA provide quantum-safe digital signatures.
Four IBM-supported signature schemes
- SQIsign
- UOV
- MAYO
- FAEST
Additional digital-signature schemes are being evaluated for future adoption, which is one more reason to stay agile.
Source: NIST, August 2024
Swapping algorithms without disruption
The ability to rapidly adapt cryptographic mechanisms in response to threats, technological advances or vulnerabilities, without disrupting infrastructure or business processes.
PQC is not a one-time replacement. Standards will evolve and new weaknesses will be found. Crypto-agility means your cryptography is inventoried, centrally governed and replaceable, so the next change is routine instead of another multi-year project.
What a crypto-agile organisation has
- A complete, up-to-date cryptographic inventory (CBOM)
- Clear ownership of keys, certificates and algorithms
- Central policies instead of hard-coded cryptography
- Suppliers that commit to quantum-safe roadmaps
- Hybrid classical + PQC where interoperability requires it
- A continuous cycle of monitoring, reporting and improvement
PQC in a few minutes
A short introduction to the quantum threat and post-quantum cryptography to share with your board, management or team.
Book an awareness workshop for your organisation