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Parallel Signatures – a relevant input to the Technology Discussion


March 22, 2024


To enhance the Swiss e-ID framework with selective disclosure while ensuring unlinkability, it’s imperative to incorporate advanced digital signature technologies such as BBS+ signatures. These technologies not only fortify the security of digital credentials but also significantly enhance user privacy. Such capabilities are crucial in minimizing the risk of personal data exposure and ensuring that users retain control over their information. It’s essential to continuously align our Trust Infrastructure with international cryptographic standards while remaining adaptable to emerging norms. This approach will facilitate interoperability across borders and sectors, ensuring that e-ID systems are both secure and universally recognized.

The parallel signatures model involves attaching multiple digital signatures to a single document or payload, with each signature providing different security or privacy features. This approach allows for a flexible and robust security framework, accommodating various cryptographic standards and privacy needs without compromising the integrity of the original document. It’s particularly useful in environments requiring adherence to diverse regulatory standards or in scenarios where resilience and both, high security and privacy are paramount. Cryptographic layering supports adaptiveness by incorporating multiple layers of cryptographic techniques within a system. This approach allows for the seamless integration and removal of cryptographic methods as needed by the Trust Ecosystem governance, enabling the system to adapt to evolving security threats and advancements in cryptographic research. It ensures long-term resilience and flexibility, allowing systems to maintain security without complete overhauls. Applying cryptographic schemes always mandates careful handling of private keys. Preventing their exposure is vital, even more so when using advanced schemes supporting derivative keys, as possible with BBS+. This underscores the need for strict security measures to prevent unauthorized access and ensure the system’s integrity.

Public-Private Partnerships (PPPs) represent a proven strategic model to operationalize digital trust and -identity solutions, combining public oversight with private sector efficiency and innovation. Such partnerships should be structured to encourage shared investment and risk, with a clear focus on public interest, global standards and local governance, protection of digital sovereignty and value-based adoption. These initiatives should be complemented by ongoing research into cryptographic innovations, preparing the ground for future advancements in e-ID security and privacy.

To address the challenges comprehensively and to build a continuously improving framework that is not only secure and compliant but also resilient and forward-looking, we must evaluate to invest in an independent body that accompanies the further progress in technology, governance and supports public and private sector adoption – to benefit from the opportunities of a trusted digital economy in the long term.

Thank you DIDAS Technology Working Group and Manu Sporny of Digital Bazaar for the dialogue!