System Design

A hybrid, multi-chain architecture bifurcating public settlement and private computation

Core Philosophy

Cylend was architected to solve the "transparency paradox" of DeFi: the tension between the need for verifiable trust (public ledger) and the need for financial privacy (institutional requirement).

The solution is a Partitioned State Model:

Public Settlement Layer (Mantle): Optimized for asset custody, high throughput, and low-cost transfers.
Private Computation Layer (Sapphire): Optimized for confidential logic, state encryption, and TEE execution.

Architectural Layers

1. The Asset Layer (Mantle)

This layer behaves like a standard DeFi protocol but is "blind" to the logic.

Components

• PrivateLendingIngress Contract
• ERC-20 Vaults
• Hyperlane Mailbox

Responsibilities

• Custody of collateral
• Emitting public events
• Executing fund releases

2. The Logic Layer (Sapphire)

The "brain" of the protocol running inside secure hardware enclaves (Intel SGX).

Components

• LendingCore Contract
• Confidential EVM (ParaTime)
• Private State Storage

Responsibilities

• Decrypting action payloads
• Calculating Health Factors
• Managing position state

3. The Data Layer (Ponder)

Unified indexing ensuring the frontend has a consistent view of the split world.

Unified Schema

type Position @entity {
  id: ID!               # User Address
  collateral: BigInt!   # From Mantle Events
  debt: BigInt!         # From Sapphire Events (Encrypted/Private)
  healthFactor: String  # Computed
}

Note

This separation of concerns allows Cylend to be solvent by proof (public verification of assets) while remaining private by design (confidentiality of user strategies).