The development of quantum computers represents one of the most significant future challenges to modern cryptography. While a fault-tolerant quantum computer capable of breaking today's public-key cryptography is not publicly known to exist, organizations must prepare for the threat now.
Contact usThe development of quantum computers represents one of the most significant future challenges to modern cryptography. While a fault-tolerant quantum computer capable of breaking today's public-key cryptography is not publicly known to exist, organizations must prepare for the threat now. The reason is simple: encrypted data can be collected today and decrypted years later when sufficiently powerful quantum computers become available.
For secure communications platforms, the challenge is particularly relevant because confidentiality often has a long lifetime. Sensitive business communications, intellectual property, legal discussions, government communications, and personal information may remain valuable for many years.
To address this challenge, we are migrating our communications platform towards post-quantum security using hybrid key negotiation mechanisms across all major key establishment protocols, including PQXDH for session establishment, Triple Ratchet for end-to-end message protection, and hybrid TLS and DTLS-SRTP for client-server communication, signaling, voice, and video traffic. By combining proven elliptic-curve cryptography with standardized post-quantum algorithms, we protect users against "harvest now, decrypt later" attacks while maintaining compatibility, performance, and security in today's environments.
For decades, the security of the Internet has relied heavily on cryptographic algorithms such as RSA and Elliptic Curve Cryptography (ECC). These algorithms protect everything from web browsing andVPN connections to secure messaging and voice and video communications.
The security of RSA and ECC is based on mathematical problems that are considered computationally infeasible for classical computers. Quantum computers fundamentally change this assumption.
Using Shor's algorithm, a sufficiently large fault-tolerant quantum computer would be able to efficiently solve the mathematical problems underlying both RSA and ECC. As a result, key exchange mechanisms that depend exclusively on these algorithms would no longer provide confidentiality against a quantum-capable adversary.
Importantly, this threat is not limited to the future. An attacker does not need a quantum computer today for the threat to be real. Instead, encrypted traffic can be recorded and stored now. Once a fault-tolerant quantum computer becomes available, the attacker can attempt to recover the historical session keys and decrypt previously captured communications. This scenario is commonly known as a "harvest now, decrypt later" attack.
Secure messaging and real-time communications are particularly exposed because they rely heavily on public-key cryptography during session establishment:
Even though the symmetric encryption used within these protocols remains largely resistant to quantum attacks, the key establishment mechanisms that create the encryption keys are vulnerable if based solely on traditional public-key cryptography.
The cryptographic community has spent years developing post-quantum cryptography (PQC): new cryptographic algorithmsdesigned to remain secure even against adversaries equipped with large-scalequantum computers.
As these algorithms mature and become standardized, the industry is moving towards their adoption. However, post-quantum cryptography is still relatively new compared to RSA and ECC, which have undergone decades of scrutiny and analysis.
For this reason, we have chosen a hybrid approach.
In a hybrid key exchange, both traditional and post-quantum algorithms contribute to the creation of the session secret. An attacker must compromise both components to break the communication. This provides two important advantages:
This approach allows us to gradually transition to post-quantum security without introducing unnecessary risk.
Within our communications platform, hybrid key establishment is being integrated into all major communication paths:
TLS Protection
TLS secures signaling, authentication services, device registration, management interfaces, and general client-server communication.
Hybrid TLS key exchanges combine classical and post-quantum key establishment methods, ensuring that encrypted traffic remains protected even if one algorithm family is eventually compromised.
DTLS-SRTP Media Protection
Voice and video communications protected by DTLS-SRTP rely on key exchanges during call setup. By introducing hybrid post-quantum key negotiation in DTLS, media session keys gain protection against future decryption attempts by quantum-capable adversaries.
This is particularly important for organizations where communication confidentiality must be preserved for many years after a call takes place.
PQXDH Session Establishment
PQXDH is responsible for establishing the initial shared secret between message conversations between users. By combining traditional elliptic-curve cryptography with post-quantum key establishment mechanisms, PQXDH provides protection against future quantum attacks while maintaining compatibility with existing deployments.
This hybrid approach ensures that session keys remain secure even if one cryptographic family is weakened in the future, providing strong protection against harvest-now-decrypt-later attacks.
Triple Ratchet
Triple Ratchet protects end-to-end encrypted conversations throughout their lifetime by continuously deriving fresh encryption keys. Building upon the security properties of Double Ratchet, Triple Ratchet incorporates both classical and post-quantum cryptographic material into the ratcheting process.
This provides forward secrecy and post-compromise security while ensuring that post-quantum protection extends beyond the initial session establishment and remains active throughout the conversation.
While hybrid key establishment significantly reduces the risk posed by harvest-now-decrypt-later attacks, the long-term transition to post-quantum security extends beyond confidentiality alone.
Today's authentication systems also relyheavily on public-key cryptography, including elliptic-curve and RSA-based digital signatures. Eventually, these systems will need to migrate towards post-quantum signature schemes to maintain equivalent security guarantees in aquantum computing era.
For many organizations, protecting confidentiality is the most urgent priority because stored encrypted data canbe harvested today. This is why our current focus is on hybrid key negotiation and secure key establishment across X3DH, TLS, and DTLS-SRTP.
As post-quantum standards continue to mature and gain operational experience, authentication mechanisms can follow the same migration path: first hybrid deployments, followed by full post-quantum adoption when confidence and ecosystem support are sufficiently mature.
The transition to post-quantum security is not a single event but a journey. By deploying hybrid cryptography today, we ensure that our communications platform remains secure against both current threats and the emerging challenges posed by future quantum computers. Most importantly, we provide protection against the harvest-now-decrypt-later threat without sacrificing the proven security properties that users depend on today.
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