Nature Communications
2019
Perfect secrecy cryptography via mixing of chaotic waves in irreversible time-varying silicon chips
Peer-reviewed article
Photonic key distribution
Pioneering the
physical future
of encryption
SEKURE is developing photonic key distribution based on chaotic light, evolving matter and irreversible physical states.
Explore the technology
TRL 4
Validation stage
Development by CUP Sciences (USA), PERA Complexity (Netherlands), the University of St Andrews (UK) and KAUST (Saudi Arabia)
The challenge
The post-quantum, AI-driven world still has a key-distribution problem
Quantum computing threatens today's public-key cryptography, while AI is increasing the scale and sophistication of cyberattacks. At the same time, autonomous systems and connected devices are multiplying the number of machine-to-machine interactions that must be trusted. Post-quantum algorithms address vulnerable mathematical methods, but still depend on secure key generation, exchange and management. Quantum Key Distribution offers a physics-based alternative, yet often requires specialised infrastructure and remains constrained by cost, distance and integration.
SEKURE has invented a new way to establish cryptographic trust directly from the physical behaviour of light and matter.
Widely deployed
Classical public-key cryptography
Security based on computational assumptions.
Specialised infrastructure
Quantum Key Distribution
Physics-based, but operationally complex.
Under experimental validation
SEKURE
Classical photonics, physical entropy and irreversible reconfiguration over conventional fibre.
How SEKURE works
Four stages, from chaotic light to reconciled key material
Stage 01
Chaotic physical interaction
Broadband optical fields interact with highly sensitive disordered photonic structures.
Stage 02
Correlated measurements
Optical reciprocity allows two remote terminals to derive correlated physical measurements.
Stage 03
Local key extraction
Each terminal extracts and reconciles key material locally. Security-critical entropy originates in the evolving photonic state.
Stage 04
Irreversible reconfiguration
After key generation, the physical structure changes, potentially removing exploitable information about the state that produced the previous key.
The current research programme is testing the operational limits, adversarial assumptions and measurable security bounds of this process.
The living photonic token
A security token that does not remain the same
SEKURE builds dynamically reconfigurable photonic tokens from photoactivated colloidal particles and hybrid silicon-colloidal structures.
A conventional physical unclonable function is frozen at manufacture: one fixed pattern of disorder, forever. SEKURE's token is time-varying — optical or thermal stimulation physically reorganises the material after every key-generation event, so the structure that produced a key no longer exists once the key is used.
This controlled evolution is engineered to:
- Maintains reliable key agreement between legitimate terminals.
- Decorrelates each new state from every previous physical state.
- Defeats prediction, cloning and post-exchange hardware capture.
- Sustains repeated reconfiguration over many operating cycles.
- Runs at telecommunications wavelengths on standard fabrication processes.
Living hardware · reconfigurable by design
Reconfiguration cycle · previous state fading
Capabilities
What the physical layer makes possible
Four properties that define the SEKURE key-distribution layer.
10⁵–10⁷×
faster than QKD
Ultra-fast key exchange
C+L
telecom bands
No quantum channels required
TI-PUF
living photonics
Physically unclonable hardware
CMOS
standard process
Scalable and cost-effective
A new trust primitive
From digital trust to physical trust
Existing cryptographic tools secure digital transactions but do not automatically establish trust between devices, sensors, materials, machines and autonomous systems.
SEKURE
physical trust primitive
Critical infrastructure
Scientific networks
Industrial control
Autonomous systems
AI-enabled devices
Sensing platforms
Network diagram: SEKURE as a shared physical trust primitive linking critical infrastructure, scientific networks, industrial control, autonomous systems, AI-enabled devices, sensing platforms and distributed cyber-physical systems.
SEKURE provides a physically grounded building block through which remote systems can establish shared cryptographic material directly from interactions between waves and matter.
In the longer term, such a primitive could support adaptive, context-specific security protocols selected by AI systems. SEKURE's current focus is the physical foundation required to make that future possible.
Research programme
From TRL 4 to a validated continuous demonstrator
TRL 4 means the core principle already works in the laboratory. The five milestones below are what remains to turn that proof into a continuously operating, independently reproducible system.
Current focus
Remaining milestones
Stage 1
Physical baseline
Characterise silicon, colloidal and hybrid token architectures.
Stage 2
Continuous operation
Automate acquisition, reconfiguration, key extraction, reconciliation and logging.
Stage 3
Network integration
Test multiplexing, amplification, fibre distance, drift and unattended operation.
Stage 4
Adversarial validation
Test replay, injection, interception, manipulation, side channels and hardware capture.
Stage 5
Independent reproduction
Deliver a transportable research demonstrator, datasets, procedures, threat model and documented failure modes.
Scientific foundations
Published science. Protected invention
Applied Physics Letters
2020
Photonics based perfect secrecy cryptography: Toward fully classical implementations
Peer-reviewed article
Patent family
Granted
Optical encryption terminals, key-distribution systems and key-generation methods
UNITED STATES (2024), CHINA (2025), EUROPE (INTENTION TO GRANT, 2026)
