/**
 * Secure random number generation utilities that work across platforms.
 * On React Native, will use expo-crypto when available for better security.
 * Falls back to platform-appropriate alternatives when needed.
 */
/**
 * Generate cryptographically secure random bytes asynchronously.
 * Preferred method on React Native when expo-crypto is available.
 *
 * @param size Number of bytes to generate
 * @returns Promise resolving to secure random bytes
 */
export declare function getSecureRandomBytesAsync(size: number): Promise<Uint8Array>;
/**
 * Generate random bytes synchronously.
 * On React Native without expo-crypto, this uses Math.random (less secure).
 * Use getSecureRandomBytesAsync() when possible for better security.
 *
 * @param size Number of bytes to generate
 * @returns Random bytes (secure on Node.js, less secure on RN without expo-crypto)
 */
export declare function getRandomBytes(size: number): Uint8Array;
/**
 * Check if secure random number generation is available on the current platform.
 *
 * @returns True if cryptographically secure RNG is available
 */
export declare function isSecureRandomAvailable(): boolean;
/**
 * Generate a cryptographically secure random hex string.
 *
 * @param length Length of the hex string (will use length/2 random bytes)
 * @returns Promise resolving to hex string
 */
export declare function getSecureRandomHexAsync(length: number): Promise<string>;
/**
 * Generate a random hex string synchronously.
 *
 * @param length Length of the hex string (will use length/2 random bytes)
 * @returns Hex string
 */
export declare function getRandomHex(length: number): string;