Update README.md to provide a comprehensive overview of The Order monorepo, including repository structure, quickstart guide, development workflow, and contribution guidelines.

packages/crypto/src/index.ts

@@ -0,0 +1,7 @@
+/**
+ * The Order Crypto Package
+ */
+
+export * from './kms';
+export * from './signature';
+

packages/crypto/src/kms.ts

@@ -0,0 +1,34 @@
+/**
+ * KMS/HSM client for key management
+ */
+
+export interface KMSConfig {
+  provider: 'aws' | 'gcp' | 'azure' | 'hsm';
+  keyId: string;
+  region?: string;
+}
+
+export class KMSClient {
+  constructor(private config: KMSConfig) {}
+
+  async encrypt(plaintext: Buffer): Promise<Buffer> {
+    // Implementation for encryption
+    throw new Error('Not implemented');
+  }
+
+  async decrypt(ciphertext: Buffer): Promise<Buffer> {
+    // Implementation for decryption
+    throw new Error('Not implemented');
+  }
+
+  async sign(data: Buffer): Promise<Buffer> {
+    // Implementation for signing
+    throw new Error('Not implemented');
+  }
+
+  async verify(data: Buffer, signature: Buffer): Promise<boolean> {
+    // Implementation for signature verification
+    throw new Error('Not implemented');
+  }
+}
+

packages/crypto/src/signature.ts

@@ -0,0 +1,33 @@
+/**
+ * Signature utilities for eIDAS/DID
+ */
+
+import { KMSClient } from './kms';
+
+export interface SignatureOptions {
+  algorithm: 'RS256' | 'ES256' | 'EdDSA';
+  keyId: string;
+}
+
+export class SignatureService {
+  constructor(private kms: KMSClient) {}
+
+  async sign(data: Buffer, options: SignatureOptions): Promise<Buffer> {
+    return this.kms.sign(data);
+  }
+
+  async verify(
+    data: Buffer,
+    signature: Buffer,
+    options: SignatureOptions
+  ): Promise<boolean> {
+    return this.kms.verify(data, signature);
+  }
+
+  async signJSON(data: unknown, options: SignatureOptions): Promise<string> {
+    const jsonString = JSON.stringify(data);
+    const signature = await this.sign(Buffer.from(jsonString), options);
+    return signature.toString('base64');
+  }
+}
+