import { ctUint256 } from './types';
/** Radix used for hex encoding/decoding in this module. */
export declare const HEX_BASE = 16;
/** Byte length of a single {@link ctUint} on the wire (ciphertext + random `r`). */
export declare const CT_SIZE = 32;
/**
 * Encodes an unsigned bigint as a fixed-width big-endian byte array.
 *
 * @param value - Integer to encode.
 * @param width - Output length in bytes; leading zero bytes are emitted as needed.
 * @returns Big-endian bytes of length `width`.
 */
export declare function bigintToBytesBE(value: bigint, width: number): Uint8Array;
/**
 * Decodes a big-endian byte array into an unsigned bigint.
 *
 * @param bytes - Non-empty byte array to decode.
 * @returns Unsigned integer represented by `bytes`.
 * @throws SyntaxError if `bytes` is empty.
 */
export declare function bytesToBigint(bytes: Uint8Array): bigint;
/**
 * Encodes bytes as a lowercase hex string (two digits per byte).
 *
 * @param bytes - Byte array to encode.
 * @returns Hex string without `0x` prefix.
 */
export declare function bytesToHex(bytes: Uint8Array): string;
/**
 * Serializes a {@link ctUint} bigint to its 32-byte on-wire representation.
 *
 * @param ciphertext - ctUint value as a bigint.
 * @returns 32-byte big-endian blob ({@link CT_SIZE} bytes).
 */
export declare function ctUintToBytes(ciphertext: bigint): Uint8Array;
/**
 * Serializes a {@link ctUint256} to a 64-byte concatenation of its two ctUint limbs.
 *
 * @param ciphertext - ctUint256 with `ciphertextHigh` and `ciphertextLow`.
 * @returns 64-byte buffer: high limb (32 B) followed by low limb (32 B).
 */
export declare function ctUint256ToBytes(ciphertext: ctUint256): Uint8Array;
/**
 * Parses a 64-byte ciphertext blob into a {@link ctUint256} object.
 *
 * @param ciphertext - 64-byte buffer (typically from encryption helpers).
 * @returns ctUint256 with `ciphertextHigh` and `ciphertextLow` bigints.
 */
export declare function ciphertextBytesToCtUint256(ciphertext: Uint8Array): ctUint256;