A Low-cost and Time-effectiveApproach for Migration of LegacyIP Networks to Post-QuantumSecurity
By
Prashant Chugh
Rakesh Singh Rawat
Centre for Development of Telematics (C-DOT), New Delhi, India
www.cdot.in
Introduction
There are two Fundamental Techniques to implement Post-Quantum Security:
➢Post-Quantum-Cryptography (PQC)
This is based on hard problems in Mathematics
➢Quantum-Key-Distribution (QKD)This is based on fundamentals of Quantum Physics
Each of these techniques has its advantages as well as disadvantages
PQC-based technique of Post-Quantum Security
Advantages
➢Minimal or No Hardware Changes required. All or most changes canusually be implemented in Software only
➢Less costly, easy to implement and easy to deploy
➢Time-effective
➢Suitable for deployment in legacy as well as green-field projects
Disadvantages
➢There are multiple categories of PQC algorithms under-standardization andwithin each category there are multiple algorithms
➢PQC algorithms are based on hard maths problems and as on date, regresscryptographic security proofs do not exist of most algorithms
QKD-based technique of Post-Quantum Security
Advantages:
➢Based on Foundations of Quantum Physics, some experts argue thatQKD is fundamentally more secure than PQC-based technique so itmay be more secure than PQC-based technique in a long-run
Disadvantages:
➢QKD-based technique requires extensive changes in Hardware
➢QKD may be more suitable for deployment in greenfield Projectsrather than in legacy projects
➢Because of costly components involved, QKD is usually much moreexpensive than PQC-based technique of Quantum-safe Security
➢More time is required for QKD implementation as well as deployment
Challenges in Implementing Post-Quantum Security in Legacy IP Networks
Challenge 1Which of the two fundamental techniques is to be used for achievingPost-Quantum Security?➢Quantum-Key-Distribution (QKD)
OR➢Post-Quantum-Cryptography (PQC)
Challenge 2If PQC is selected for implementation, then also an implementer is indilemma to select a particular➢PQC algorithm category➢PQC candidate algorithm within that category
Challenge 3
Legacy IP Networks carry live traffic so Downtime during Quantum-safemigration has to be minimal. Hence, Migration has to be time-effective.
Challenge 4
Legacy IP Network have very Limited Budgets available for Support andEnhancements. Hence, Quantum-safe migration has to be low-cost.
Challenge 5
Many stakeholders managing Legacy IP networks currently believe that thethreat from Quantum computers is not immediate so they do not want toinvest immediately in Quantum-safe migration. Hence, we need to have agraded-response based strategy for Quantum-safe migration i.e.investment in Quantum-safe migration should be currently minimal andincrease as the threat perception increases.
continued….Challenges in Implementing Post-Quantum Security in Legacy IP Networks
A Simplistic Representative View of our Legacy IP Network which is to be migrated to Post-Quantum Security
IP-Servers
Networking Cloud (Multiple L2
Switches and/or L3 IP Routers)
IP-Servers
IP-Phones
Lab Experiments to evolve Migration Approach
Experiment 1
Implementation of PQC algorithms in end devices of Legacy IP
Network
➢Hybrid key-exchange combining classical key-exchange with Post-Quantumkey-exchange of at least one lattice-based key-exchange and/or one code-based key exchange was implemented
➢Symmetric Encryption/Decryption Algorithm as AES-256 was implemented
Lessons Learnt:
➢Software changes can be done for those end devices which were in-housedeveloped. It was sometimes very difficult to do these changes for COTSdevices
Experiment 2Development of a Network-Layer Encryption Product
➢This product for Encryption at Network Layer implements:▪ Hybrid key-exchange combining classical key-exchange with Post-Quantum
key-exchange of at least one lattice-based key-exchange and/or one code-based key exchange
▪ Symmetric Encryption/Decryption of data using AES-256 algorithm
➢This product was used as a network gateway of those IP end deviceswhere knowhow of communication software was not available
Lessons Learnt:
➢A network-layer encryption product helps to enable PQC for IP enddevices where knowhow of communication software was notavailable in-house (such as COTS devices)
Experiment 3Enhancements in Network-layer Encryption product to accept keys from an external QKD-based system
➢Software on network-layer Encryption product was enhanced to acceptcipher keys from an external QKD-based system
➢Configuration options have been provided to either use the cipher keysgenerated using Hybrid key-exchange or the ones that have been sent byan external QKD-based system (or a combination of both)
Lessons Learnt:
➢PQC-based hybrid-key exchange is used currently in Network-layerEncryption product. The additional configuration Capability to use keysfrom QKD-based system allows QKD-based migration in future
A Simplistic Representative View of our Legacy IP Network after Proof-of-Concept Quantum-Safe Migration in Lab
IP-Servers
Networking Cloud (Multiple L3 IP Routers)
IP-Servers
L2-Switch
L2-Switch
PQC-Enabled Network Layer Encryptor
PQC-EnabledNetwork-layer Encryptor
PQC-EnabledNetwork-Layer Encryptor
PQC-Enabled Network-Layer Encryptor
L2-SwitchPQC-Enabled Network-Layer Encryptor
QKD * System
QKD * System
QKD * System
* External System (Not a part of Network-layer Encryptor)
IP-Phones
SUMMARY➢Implementation of only PQC-based technique currently and keeping a
provision for using a QKD-based approach in future is our solution to thechallenge of selecting the Quantum-safe migration technique for Legacy IPNetworks
➢Implementation of multiple under-standardization PQC algorithms andusing it in a hybrid manner with classical key-exchange solves the problemof selection of one PQC algorithm
➢Implementation of only PQC-based technique currently for Quantum-safemigration solves the challenge of not-only keeping the cost low but also thechallenge of keeping implementation & deployment time-effective
➢Implementation in a Network-layer Encryption product rather than in alarge number of diverse IP end devices helps in keeping migration time-effective
➢Configuration Capability in Network-layer Encryption product to use keysfrom QKD-based system in future helps in making a graded-response-basedmigration strategy
THANK YOU
E-mail: Prashant Chugh <[email protected]> Rakesh Singh Rawat <[email protected]>
www.cdot.in
