ZKP-IDFS: A Zero-Knowledge Proof-Based Digital Identity Framework for Financial Inclusion in Sub-Saharan Africa

Financial exclusion remains acute in Sub-Saharan Africa, where more than 350 million adults lack access to formal financial services. A defining barrier is the absence of verifable identity: in countries such as Mozambique, Tanzania, and Niger, over half of adults without mobile money accounts cite missing documentation as the primary obstacle. Existing remedies either centralise sensitive personal data, creating systemic privacy and security risks, or demand document-issuing infrastructure that does not yet exist in many communities. This paper proposes ZKP-IDFS (Zero-Knowledge Proof Identity for Financial Services), a decentralised, privacy preserving digital identity framework that lets individuals prove identity-related predicates to financial institutions without disclosing the underlying personal attributes. ZKP-IDFS combines Groth16 zk-SNARKs for succinct on-chain proof verification, Pedersen commitments for attribute hiding, a W3C-compliant Verifi-able Credential layer, and a lightweight USSD/SMS proof-relay channel designed for feature-phone users in low-connectivity environments. We formalise the cryptographic model, specify the system architecture, and present a simulated performance evaluation across four representative network conditions. Results from a controlled simulation study show that end-to-end proof generation and relay complete in under 4.2 seconds on entry-level Android handsets at 3G speeds, with on-chain verication costs below 0.003 USD on an EVM-compatible layer-2 chain; these results require validation in eld deployments. We further demonstrate compliance with FATF risk-based KYC guidance and with emerging African data-protection legislation.