/// <reference types="node" />
export type CommitmentSecretStoreItem = {
    index: bigint;
    secret: Buffer;
};
/**
 * Defined in BOLT3, this class compactly stored received commitment
 * secrets from our counterparty. Without this mechanism we are required
 * to store every commitment secret that we receive (2^48) which can be
 * a huge amount of data at 32-bytes per secret.
 *
 * Instead we can use the fact that later commitment secrets act as
 * prefixes for prior commitment secrets. We can then compactly store
 * only the secrets we need to derive older commitment secrets.
 */
export declare class CommitmentSecretStore {
    /**
     * Returns the index of the least-significant bit. This is used to
     * determine what the value at I is a prefix for.
     * @param I commitment
     */
    static calcIndex(I: bigint): number;
    private secrets;
    constructor();
    /**
     * Insert the commitment secret into the store and verify that the
     * secret is able to derive all prior commitment secrets that we
     * already know about.
     *
     * @param secret 32-byte secp256k1 secret
     * @param i commitment number
     */
    insert(secret: Buffer, i: bigint): void;
    /**
     * Derives old commitment secrets from the from the compact store.
     * Throws if we do not have the commitment secret for the specified
     * commitment nmber.
     * @param i derivation number starting at 2^48-1 down to zero.
     */
    derive(i: bigint): Buffer;
}