POS Financial Key Download Using Two-Stage ECDH Authentication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing financial certificate and financial key download method in POS machines lacks sufficient security, particularly during the injection of master and working keys into POS devices, as it relies on insecure RSA2048 algorithm and one-way authentication.
Innovation Solution
Implementing an Elliptic Curve Diffie-Hellman (ECDH) key negotiation algorithm for session key negotiation between a key distribution host and a key receiving device to establish secure channels, followed by two rounds of session key negotiations and authentication to ensure secure financial certificate and key download.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RSA2048 algorithm and one-way authentication are used for financial key download, then the download process can be completed, but the security of the download is insufficient
Solution Approach 1:
The authentication process is segmented into two distinct phases: certificate authentication (downloading the CA certificate) and key authentication (downloading the financial key). Each phase has its own dedicated session key (first session key for certificate, second session key for key), ensuring that compromise in one phase does not affect the other. This segmentation enhances security while maintaining manageable complexity through clear separation of concerns.
Solution Approach 2:
The certificate is downloaded and authenticated before the financial key is downloaded. This preliminary action establishes a trusted foundation by first verifying the identity of the key distribution host through certificate authentication. Only after successful certificate verification is the financial key downloaded, ensuring that the key receives protection from a pre-established secure channel.
2Reliability
If one-way authentication protocol is used, then the key distribution host can download keys to POS device, but mutual authentication between host and device cannot be ensured
Solution Approach 1:
The system implements feedback mechanisms in both authentication phases. During certificate authentication, the POS device verifies the host's certificate and sends acknowledgment. During key authentication, the device verifies the host's identity again using the newly established secure channel. This feedback loop ensures mutual authentication while maintaining operational simplicity through automated verification processes.
3Reliability
If financial certificate and key are downloaded in single authentication phase, then the process is simpler, but security is compromised
Solution Approach 1:
The download process is divided into periodic phases with distinct security objectives. The first phase (certificate download) establishes trust infrastructure. The second phase (key download) utilizes the established trust for secure key transmission. This periodic structure with clear boundaries ensures comprehensive security while optimizing time by avoiding redundant authentication steps within each phase.
Data Source
Figure 1
Figure 2
AI summary
The present invention discloses a financial certificate and financial key download method and system. The method comprises: performing a session key negotiation between a key distribution host end and a key receiving device end using an ECDH key negotiation algorithm to obtain a first session key; sending, via the key receiving device end, a financial certificate download request to the key distribution host end; generating, via the key distribution host end, a financial certificate , and sending to the key receiving device end; performing a session key negotiation between the key distribution host end and the key receiving device end based on the financial certificate again to obtain a second session key; sending, via the key receiving device end, a financial key download request to the key distribution host end; and generating, via the key distribution host end, a financial key, and sending to the key receiving device end.