Verify user identity with one-time codes across channels

flowchart TD trig>"user requests identity verification"]:::trig s0["generate and store passcode"]:::task s1["send code to user"]:::svc s2["verify entered code"]:::task s3["confirm or reject identity"]:::task trig --> s0 s1 --> s2 s2 --> s3 gx{"× which channel used"}:::gate s0 --> gx p00["send code via whatsapp"]:::task gx -->|"whatsapp"| p00 p10["send code via telegram"]:::task gx -->|"telegram"| p10 p20["send code via email"]:::task gx -->|"email"| p20 jn{"○ code delivered"}:::gate p00 --> jn p10 --> jn p20 --> jn jn --> s1 out[/"pass or fail verification result"/]:::out pay{{"secure onboarding across channels"}}:::pay s3 --> out out --> pay classDef task fill:#e7f6fe,stroke:#34b8f0,color:#2c2a29 classDef svc fill:#f6f8fa,stroke:#7c8795,color:#2c2a29 classDef mi fill:#e7f6fe,stroke:#0079a8,color:#2c2a29,stroke-width:2px classDef human fill:#fff,stroke:#0079a8,color:#0079a8 classDef store fill:#f6f8fa,stroke:#0079a8,color:#2c2a29 classDef trig fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigtime fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigdata fill:#8ad4f5,stroke:#0079a8,color:#06314c,font-weight:bold classDef gate fill:#fff,stroke:#e8a23d,color:#6b4708,font-weight:bold classDef out fill:#1f9d6b,stroke:#167a53,color:#fff,font-weight:bold classDef pay fill:#06314c,stroke:#021f33,color:#fff