/** Hex string to Uint8Array. Accepts lowercase/uppercase, optional 0x prefix. Throws RangeError on odd-length or non-hex input. */
export declare const hexToBytes: (hex: string) => Uint8Array;
/** Uint8Array to lowercase hex string. */
export declare const bytesToHex: (bytes: Uint8Array) => string;
/** UTF-8 string to Uint8Array. */
export declare const utf8ToBytes: (str: string) => Uint8Array;
/** Uint8Array to UTF-8 string. */
export declare const bytesToUtf8: (bytes: Uint8Array) => string;
/** Base64 or base64url string to Uint8Array. Handles padded, unpadded, and legacy %3d padding. Throws RangeError on invalid input. */
export declare const base64ToBytes: (b64: string) => Uint8Array;
/** Uint8Array to base64 string. Pass url=true for base64url (RFC 4648 §5, no padding characters). */
export declare const bytesToBase64: (bytes: Uint8Array, url?: boolean) => string;
export declare const CTE_MAX_BYTES = 32768;
/**
 * Constant-time byte-array equality.
 * Runs entirely inside a WASM SIMD module (v128 XOR accumulate with
 * branch-free reduction). Throws on runtimes without SIMD support,
 * no JS fallback. Length check is not constant-time (length is
 * non-secret in all protocols). Max input size: 32768 bytes per side.
 */
export declare const constantTimeEqual: (a: Uint8Array, b: Uint8Array) => boolean;
/** Zero a typed array in place. */
export declare const wipe: (data: Uint8Array | Uint16Array | Uint32Array) => void;
/** XOR two equal-length Uint8Arrays, returns new array. */
export declare const xor: (a: Uint8Array, b: Uint8Array) => Uint8Array;
/** Concatenate one or more Uint8Arrays into a new array. */
export declare const concat: (...arrays: Uint8Array[]) => Uint8Array;
/** Cryptographically secure random bytes via Web Crypto API. */
export declare const randomBytes: (n: number) => Uint8Array;
/**
 * Detects WASM SIMD support once and caches the result.
 * Used by init() to preflight-check before loading serpent/chacha20 modules.
 * Exported for consumers who want to feature-detect before calling init().
 */
export declare function hasSIMD(): boolean;