WDB160 Universal Hash Function

Overview

WDB160 is a deterministic hash function that generates 160-bit identifiers from any combination of inputs. It creates consistent, collision-resistant document IDs for WeaveDB while maintaining compatibility with blockchain addresses and cross-chain applications.

The Problem

WeaveDB applications need deterministic document IDs that:

• Fit within 254-bit constraints due to BN254 zk-circuit limitations
• Handle multiple inputs of varying types and lengths
• Maintain consistency across different data types and encodings

The Solution: WDB160

WDB160 creates a uniform 160-bit hash from any inputs:

160 bits = 20 bytes < 254 bits ✅ (Fits WeaveDB constraint)

Function Signature

wdb160(inputs)

Parameters

• inputs: Array of values to hash (any JavaScript types)

Returns

• String: URL-safe base64 encoded hash (27 characters)

Basic Usage

// WeaveDB document IDs
const followId = wdb160(["user123", "user456"])
// Result: "k2B9mK8vN3pQ7xR5tL6wA9cF1eD"
 
// Mixed data types
const complexId = wdb160([42, "hello", {user: "alice"}])
// Result: "xN4mL9rT8kE2vQ6wP5cA1bG7hJ3"
 
// Blockchain addresses
const multisigId = wdb160([
  "0x742d35Cc6634C0532925a3b8D39391F23169e22F",
  "0x8ba1f109551bD432803012645Hac136c29F657D"
])

Advanced Features

Type Specification

// Explicit encoding types
const hexId = wdb160([["deadbeef", "hex"], ["hello", "utf8"]])
const b64Id = wdb160([["SGVsbG8=", "base64"], ["world"]])

Auto-Detection

• WDB23 Addresses: 31-character strings automatically detected as base64url
• Hex Strings: "0x" prefixed strings handled as hex
• JavaScript Types: Objects/arrays converted via JSON.stringify

Type Conversion

Security Properties

Collision Resistance

• 160-bit output = 2^80 collision resistance
• Same security level as Ethereum addresses
• Effectively collision-free for all real-world applications

Deterministic

• ✅ Same inputs always produce same output
• ✅ Platform independent
• ✅ Version stable

Implementation

Internal Algorithm

1. Convert all inputs to buffers with specified encoding
2. Concatenate buffers into single input
3. Apply Keccak256 hash
4. Truncate to 160 bits (20 bytes)
5. Encode as URL-safe base64

Keccak256 Foundation

• ✅ Cryptographically secure (SHA-3)
• ✅ Uniform output distribution
• ✅ Battle-tested (used by Ethereum)

Output Format

• Character set: A-Z, a-z, 0-9, -, _
• Length: Always 27 characters (no padding)
• Size: Always 160 bits (20 bytes)
• URL safe: Works in URLs and filenames
• Database safe: Perfect for document IDs

WeaveDB Integration

// Document ID generation
const relationshipId = wdb160(["follower_addr", "following_addr"])
 
// Schema validation
const schema = {
  relationships: {
    properties: {
      id: { type: "string", pattern: "^[A-Za-z0-9_-]{27}quot; }
    }
  }
}

Best Practices

Input Ordering

// ✅ Sort inputs for consistency
const addresses = [addr1, addr2].sort()
const id = wdb160([addresses])
 
// ❌ Order matters - these produce different hashes
wdb160(["alice", "bob"])  // Different from:
wdb160(["bob", "alice"])

Domain Separation

// ✅ Add context to prevent collisions
const followId = wdb160(["alice", "bob", "follow"])
const chatId = wdb160(["alice", "bob", "chat"])

Key Benefits

✅ WeaveDB Optimized - 160 bits fits comfortably within 184-bit optimal setting
✅ Universal Input Support - Handles any JavaScript type
✅ Production Ready - Battle-tested cryptography
✅ Developer Friendly - Simple API with smart defaults

WDB160 provides the universal hashing foundation for optimized WeaveDB document IDs! 🎯