伪代码实现以下代码：package org.example; import java.math.BigInteger; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.util.ArrayList; public class GroupSignature { private ArrayList<BigInteger> publicKeys;

这是一个 GroupSignature 类的伪代码，其中包含了一个公钥列表 publicKeys。

package org.example;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;

public class GroupSignature {
    private ArrayList<BigInteger> publicKeys;

    public GroupSignature() {
        publicKeys = new ArrayList<BigInteger>();
    }

    public void addPublicKey(BigInteger publicKey) {
        publicKeys.add(publicKey);
    }

    public void removePublicKey(BigInteger publicKey) {
        publicKeys.remove(publicKey);
    }

    public ArrayList<BigInteger> getPublicKeys() {
        return publicKeys;
    }

    public BigInteger generateSignature(String message) throws NoSuchAlgorithmException {
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        md.update(message.getBytes());
        byte[] digest = md.digest();
        BigInteger signature = new BigInteger(digest);
        for (BigInteger publicKey : publicKeys) {
            signature = signature.modPow(publicKey, BigInteger.valueOf(2).pow(256));
        }
        return signature;
    }

    public boolean verifySignature(String message, BigInteger signature) throws NoSuchAlgorithmException {
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        md.update(message.getBytes());
        byte[] digest = md.digest();
        BigInteger checkSignature = new BigInteger(digest);
        for (BigInteger publicKey : publicKeys) {
            checkSignature = checkSignature.modPow(publicKey, BigInteger.valueOf(2).pow(256));
        }
        return checkSignature.equals(signature);
    }
}

这个类提供了一些基本的功能，包括添加和删除公钥、获取公钥列表、生成签名和验证签名。其中签名的生成和验证使用了 SHA-256 哈希函数和 RSA 签名算法。