Glossary
This reference defines technical terms used throughout Silhouette documentation.
A
AES-GCM
Advanced Encryption Standard with Galois/Counter Mode. Symmetric encryption algorithm that encrypts order details and communications between browser and enclave.
Agent Wallet
Fresh Hyperliquid wallets used to execute aggregated trades on HyperCore. Maximises privacy by obscuring individual trader activity during settlement.
Allowlist
Curated list of users authorised to place orders on Silhouette MVP. Any user may deposit regardless of allowlist status.
Attestation
CBOR-encoded, COSE-signed documents from Nitro Hypervisor that verify the exact code running inside an enclave. Proves computational integrity.
C
CBOR
Concise Binary Object Representation. Encoding format for attestation documents that enables efficient binary serialisation.
Cipher-text
Encrypted data resulting from encryption of plaintext order details. Only decryptable by intended recipients.
COSE
CBOR Object Signing and Encryption. Signing format for attestation documents that ensures authenticity and integrity.
E
ECDH
Elliptic Curve Diffie-Hellman. Key agreement protocol enabling two parties to establish a shared secret over insecure channels.
EIF
Enclave Image File. Contains application and runtime dependencies for deployment to Nitro Enclave. Hash determines PCR0 value.
Enclave
See Trusted Execution Environment (TEE).
Encryption Key
AES symmetric key derived from X25519 key exchange that shields balances and trading activity from all parties except the trader.
End-to-End Encryption
Encryption where only communicating parties (browser and enclave) can decrypt information. No intermediaries have access.
G
Good Til Cancelled (GTC)
Default order type in Silhouette. Remains active until filled, cancelled, or expired.
H
HKDF
HMAC-based Key Derivation Function. Derives encryption keys from X25519 shared secrets for secure communication.
HyperBFT
Consensus mechanism securing the unified Hyperliquid blockchain containing both HyperCore and HyperEVM.
HyperCore
High-performance trading component of Hyperliquid. Purpose-built for financial primitives with sub-millisecond execution.
HyperEVM
Ethereum Virtual Machine-compatible component of Hyperliquid. Supports smart contracts with fast and slow execution blocks.
I
Immediate or Cancel (IOC)
Order type used when Silhouette orders expire and are placed on Hyperliquid exchange. Executes immediately or cancels remainder.
IndexedDB
Browser storage where private encryption keys are stored locally. Namespaced by account address and network ID.
K
KDF
Key Derivation Function. Cryptographic primitive that expands key material into one or more cryptographic keys.
L
L1
Deprecated term for HyperCore. Previously used to refer to the main Hyperliquid blockchain layer where final settlement occurs.
Limit Order
Order to buy or sell at specific price or better. Provides price protection for traders.
M
Managed Wallet
Ephemeral wallet created in trader's browser. Authorised to submit orders on behalf of primary account for frictionless trading.
Market Order
Order to buy or sell immediately at current market price. Prioritises execution speed over price control.
Matching Engine
System that matches buy and sell orders according to price-time priority rules. Runs inside secure enclave.
N
Nix
Deterministic build system used by Silhouette to achieve reproducible builds of enclave code.
Nonce
Number used once in cryptographic operations. Ensures security and prevents replay attacks.
O
Order Book
List of buy and sell orders for trading pair. Maintained privately within secure enclave.
Order Expiry
Timestamp after which order expires in Silhouette's order book and gets settled on HyperCore.
P
Partial Fill
When order is only partially executed, leaving remaining balance to be filled later.
PCR0
Platform Configuration Register 0. SHA-384 hash of enclave image file that definitively identifies exact code running inside Nitro Enclave.
Perps
Perpetual futures contracts. Currently unsupported on Silhouette but available on Hyperliquid.
Price-Time Priority
Matching algorithm that prioritises orders first by price, then by timestamp for orders at same price level.
Primary EVM Wallet
Root wallet (MetaMask, WalletConnect, Frame) that controls Silhouette account and performs critical functions like deposits.
S
Settlement
Final execution and clearing of trades. Occurs on HyperCore for expired orders through agent wallets.
Shared Secret
Cryptographic secret derived through X25519 ECDH between webapp and enclave for secure communication.
Shielded Exchange
Privacy-preserving trading platform that protects order flow from public visibility while maintaining full functionality.
Silhouette Contract
Primary smart contract deployed on HyperEVM. Orchestrates exchange operations and stores encrypted state.
Silhouette UI
Frontend interface enabling direct HyperCore actions, Silhouette Contract interaction, and encryption key management.
Spot Trading
Direct trading of tokens (as opposed to derivatives). Supported on both Silhouette and Hyperliquid.
Strategy Protection
Ability to trade without signalling intentions or revealing strategies to other market participants.
szDecimals
Hyperliquid's precision specification for token amounts. ETH has szDecimals of 4, meaning prices are quoted to 4 decimal places.
T
TEE
Trusted Execution Environment. Secure, isolated computing environment enabling confidential computation. Silhouette uses AWS Nitro Enclaves.
U
UI Encryption Key
X25519 key pair generated in browser for encrypting communications with secure enclave. Private component never leaves browser.
X
X25519
Elliptic curve in Montgomery form over field with 2^255 + 19 elements. Used for Diffie-Hellman key exchange to establish shared secrets between webapp and enclave.
ℹ️ Info: This documentation is for informational purposes only and does not constitute financial advice.