# Architecture II Drey Finance consists of two major components. First, there is a [Proof of Life app](#proof-of-life-app) for iOS and Android whose main function is to verify the liveliness of the Drey customer so that they can receive their monthly annuity payment. In addition, the app enables a customer to get up to the second accurate information on payout, yield income generated and other operations. Second, the Drey Decentralized Actuary Network is a federation consisting of independent parties using their instance of [Drey's Actuary Client software](https://drey-finance.gitbook.io/drey-finance/architecture-iii#drey-actuary-client), with communication conducted using the [Nostr protocol](https://nostr.com/). Drey Actuary Clients coordinate over Nostr to action actuarial processes and wallet operations for the benefit of the Drey customers. Drey Actuary Clients also serve information to Drey customer's on their instances of the Drey Proof of Life App.

Figure 4. Drey Finance Architecture

## Proof of Life App Drey's Proof of Life app delivers more functionality that just verifying the liveliness of customer. It is the primary method of interacting with the Drey Finance decentralized actuarial operating system. The Proof of Life App's main functions include the following: * Demographic Verification * Proof of Life Verification * Account Settings & Information * Fiat on-ramp / off-ramp ### Demographic Verification The app verifies the age, sex and geography of Drey Fund investors during enrolment. This information is obtained via third party identity and KYC service providers contracted to Drey Finance. The user experience will be akin to signing up to any centralised exchange or finance institution, and should be less painful, as the amount of information necessary to obtain and verify is small: * Age * Birth Month and Year * Citizenship * Country of Residence Note that name, address or any other personally identifying information IS NOT required to be stored on an ongoing basis, and none is. Instead, a content-based GUID ([RFC 4122](http://www.ietf.org/rfc/rfc4122.txt) describes the conventions) is created from the obtained information and this applies as the unique identifier for the Drey Fund investor. Drey Actuaries are never party to, and will never know, any personally identifying information of a Drey Fund investor (such as name or address). The Drey Proof of Life App is configured to comply with U.S. State Department terrorism watch list and EU sanctions list, so any identities from these geographies (North Korea, Iran, Syria, etc.) are not eligible to create Drey Fund accounts and will not be serviced. ### Proof of Life Verification Here again, Drey utilizes [zero knowledge proof technology](https://en.wikipedia.org/wiki/Zero-knowledge_proof) to authenticate a user to the Drey Actuary network without revealing any personally identifying details. As described in [following sections](https://drey-finance.gitbook.io/drey-finance/cryptography-overview), zero-knowledge proof technology is a cryptographic method that allows one party (the prover) to prove to another party (the verifier) that they know a specific piece of information without revealing that information itself. Not only is this useful to verify correct computation, this technology is particularly useful for authentication processes where the goal is to verify an identity without revealing any personally identifiable information. In the context of the technology used in Drey Finance, the zero-knowledge proof technology works by using a [multi-factor authentication protocol](https://milagro.apache.org/docs/milagro-protocols/) built upon zero-knowledge proofs. When a user wants to authenticate themselves, they create a proof that shows they know how to re-create their secret information (a private key) from something they have (a device), something they know (a pin) and something they are (a biometric) without actually revealing that secret information. This proof is then sent to the verifier. The verifier, having the public information corresponding to the user's secret, can verify the proof without learning anything about the user's secret. This is the "zero-knowledge" aspect of the protocol. If the proof is valid, the verifier can be sure that the user knows their secret, and thus the user's identity is authenticated. This process removes the need for a traditional Public Key Infrastructure (PKI) system, where certificates are issued to bind a public/private key pair to an identity. Instead, the identity management and key lifecycle can take place within the decentralized actuarial operating system itself. In certain use cases, this technology can make systems easier to scale and manage than traditional PKI, eliminate root key 'single point of compromise' weaknesses, and provide a seamless fit for today's decentralized networks and distributed systems. After the initial enrolment workflow is completed for identity verification, each month, when the customer's Drey distribution is ready to obtained, the customer simply opens their Drey app, authenticates with FaceID, inputs a six digit pin, and the Proof of Life process is complete. The experience is seamless and frictionless. Once authenticated into the app the Drey customer can obtain principal balances, opt-in/out of yield generation programs, view expected portfolio returns, and/or select fiat off-ramps for their distributions, among other actions. ### Account Settings and Information The Proof of Life app will also enable users to configure their settings for: * Alerts, notifications * Opt-in to other yield generation programs * Fiat-off ramps * Setup additional accounts (for couples or children) ### Fiat on-ramps/off-ramps The Drey Proof of Life app also enables distributions to be automatically converted to fiat, with distributions directed to Drey Finance's exchange partners over the [lightning network](https://lightning.network/). Drey Finance will negotiate the best exchange rate by volume with partners on behalf of the Drey customer, and utilize the lightning network to make instant payments to the exchange partner. The app will enable the user to setup their own remittance information with the exchange partner's database through an integration into their API. It is envisioned that a number of exchange partners will be utilized and enabled based on geography and regulatory requirements. This same infrastructure will be utilized for fiat on-ramps. The Drey Proof of Life app will enable, post identity verification and enrolment, a user to utilize bank accounts and/or debit cards to fund their account to the best extent possible for that user's given geography and jurisdiction. The app's emphasis on user experience and design for on-boarding (and use of AI) will prompt the user the best/easiest way to fund their account as a main design objective.