/**
 * AvoEncryption — React Native ECIES encryption using @noble/ciphers.
 *
 * CRITICAL: React Native's Hermes runtime does NOT have crypto.subtle.
 * This module uses @noble/ciphers/aes gcm() for AES-GCM instead — fully synchronous.
 * Ephemeral key generation and ECDH use @noble/curves/p256.
 *
 * Wire format (MUST match all SDKs):
 *   [0x00][65-byte ephemeral pubkey (uncompressed)][16-byte IV][16-byte auth tag][ciphertext]
 *   → base64
 *
 * Algorithm:
 *   1. Generate ephemeral P-256 key pair
 *   2. ECDH: ephemeral private key + recipient public key → shared secret (X-coordinate)
 *   3. KDF: SHA-256(shared secret) → 32-byte AES key
 *   4. AES-256-GCM encrypt with random 16-byte IV
 *   5. Serialize: version(1) + ephemeralPubKey(65) + IV(16) + authTag(16) + ciphertext
 *   6. Base64 encode
 */
/**
 * Determines whether encryption should be performed.
 *
 * Truth table:
 *   dev + key → true
 *   staging + key → true
 *   prod + key → false
 *   dev + null → false
 *   dev + empty → false
 */
export declare function shouldEncrypt(env: string, publicEncryptionKey: string | null | undefined): boolean;
/**
 * Encrypts a value using ECIES (P-256 ECDH + AES-256-GCM).
 * Fully synchronous — no async/await.
 *
 * @param value - The plaintext string to encrypt (already JSON-stringified by caller if needed)
 * @param publicKeyHex - The recipient's P-256 public key as a hex string (uncompressed, 04...)
 * @returns Base64-encoded ciphertext in Avo ECIES wire format
 */
export declare function encryptValue(value: string, publicKeyHex: string): string;
/**
 * Encrypts event property values for transmission.
 *
 * Rules:
 * - List-type properties are omitted entirely
 * - On encryption failure: console.warn, omit the property, continue
 * - Returns new array with encryptedPropertyValue set (propertyType/propertyName preserved)
 */
export declare function encryptEventProperties(properties: Array<{
    propertyName: string;
    propertyType: string;
    children?: any;
    failedEventIds?: string[];
    passedEventIds?: string[];
}>, eventProps: Record<string, any>, publicKeyHex: string): Array<{
    propertyName: string;
    propertyType: string;
    encryptedPropertyValue?: string;
    children?: any;
    failedEventIds?: string[];
    passedEventIds?: string[];
}>;