本文主要是介绍JPBC密码学库封装函数，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
package Util; /*** FileName: Util.Util* Author: star* Date: 2019/10/24 17:27* Description: 一些公共的处理参数或者返回结果的方法* History:* <author> <time> <version> <desc>* 作者姓名 修改时间 版本号 描述*/import BCPA.roles.BCPA_PKG;
import it.unisa.dia.gas.jpbc.Element;
import it.unisa.dia.gas.jpbc.Pairing;import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.util.ArrayList;
import java.util.List;/*** 〈一句话功能简述〉<br> * 〈一些公共的处理参数或者返回结果的方法〉** @author star* @create 2019/10/24* @since 1.0.0*/
public class Util {private static final char[] HEX_ARRAY = "0123456789ABCDEF".toCharArray();private static Pairing pairing;//从PKG设置pairing方便后续使用public static void setPairing(Pairing pairing) {Util.pairing = pairing;}//16进制的byte[]数组转换为字符串public static String hexBytesToString(byte[] bytes) {char[] hexChars = new char[bytes.length * 2];for (int j = 0; j < bytes.length; j++) {int v = bytes[j] & 0xFF;hexChars[j * 2] = HEX_ARRAY[v >>> 4];hexChars[j * 2 + 1] = HEX_ARRAY[v & 0x0F];}return new String(hexChars);}//16进制的字符串转换为byte[]数组public static byte[] hexStringToBytes(String s) {int len = s.length();byte[] data = new byte[len / 2];for (int i = 0; i < len; i += 2) {data[i / 2] = (byte) ((Character.digit(s.charAt(i), 16) << 4)+ Character.digit(s.charAt(i+1), 16));}return data;}//G1中获取随机元素，获取1，获取0public static Element getRandomFromG1() {return pairing.getG1().newRandomElement().getImmutable();}public static Element getOneFromG1() {return pairing.getG1().newOneElement().getImmutable();}public static Element getZeroFromG1() {return pairing.getG1().newZeroElement().getImmutable();}//Zp中获取随机元素，获取1，获取0public static Element getRandomFromZp() {return pairing.getZr().newRandomElement().getImmutable();}public static Element getOneFromZp() {return pairing.getZr().newOneElement().getImmutable();}public static Element getZeroFromZp() {return pairing.getZr().newZeroElement().getImmutable();}//H1,H2 : {0, 1}∗ → G1public static Element hashFromStringToG1(String str) {return pairing.getG1().newElement().setFromHash(str.getBytes(), 0, str.length()).getImmutable();}public static Element hashFromBytesToG1(byte[] bytes) {return pairing.getG1().newElement().setFromHash(bytes, 0, bytes.length).getImmutable();}//H : {0, 1}∗ → Zppublic static Element hashFromStringToZp(String str) {return pairing.getZr().newElement().setFromHash(str.getBytes(), 0, str.length()).getImmutable();}public static Element hashFromBytesToZp( byte[] bytes) {return pairing.getZr().newElement().setFromHash(bytes, 0, bytes.length).getImmutable();}//h : G1 → Zppublic static Element hashFromG1ToZp( Element g1_element) {// h(y) : G1 -> Zpbyte[] g1_bytes = g1_element.getImmutable().toCanonicalRepresentation();byte[] zp_bytes = g1_bytes;try {MessageDigest hasher = MessageDigest.getInstance("SHA-512");zp_bytes = hasher.digest(g1_bytes); //先把G1元素hash成512bits} catch (Exception e) {e.printStackTrace();}//再把hash后的bits映射到ZpElement hash_result = pairing.getZr().newElementFromHash(zp_bytes, 0, zp_bytes.length).getImmutable();return hash_result;}//{0,1}* -> key space of πkey int空间public static int h1_pai_key(String data) {try {MessageDigest hasher = MessageDigest.getInstance("SHA-256");byte[] result = hasher.digest(data.getBytes());ByteBuffer wrapped = ByteBuffer.wrap(result);return wrapped.getShort();} catch (Exception e) {e.printStackTrace();return -1;}}//伪随机置换 pseudorandom permutation πkey() 用于随机选择哪些块进行抽查public static List<Integer> pseudoPerm(int key, int n, int c) {List<Integer> result = new ArrayList<Integer>(c);if(c < n) {List<Integer> list = new ArrayList<>(n);for(int i = 0; i < n; i ++) {list.add(i);}for(int i = 0; i < key; i ++)java.util.Collections.shuffle(list);for(int i = 0; i < c; i ++) {result.add(list.get(i));}} else {System.out.println(" pseudorandom permutation error!");}return result;}//{0,1}* -> key space of fkey 字符串空间public static String h2_f_key(String data) {try {MessageDigest hasher = MessageDigest.getInstance("SHA-512");byte[] result = hasher.digest(data.getBytes());return result.toString();} catch (Exception e) {e.printStackTrace();return "error";}}//伪随机函数 pseudorandom function fkey():{0,1}* -> Zppublic static Element pseudoFunc(String key, int id) {try {MessageDigest hasher = MessageDigest.getInstance("SHA-512");byte[] hash_bytes = hasher.digest((key + id).getBytes()); //先把G1元素hash成512bitsreturn pairing.getZr().newElementFromHash(hash_bytes, 0, hash_bytes.length).getImmutable();} catch (Exception e) {e.printStackTrace();return pairing.getZr().newRandomElement();}}public static void main(String[] args) throws Exception {BCPA_PKG pkg = new BCPA_PKG();System.out.println(Util.hashFromStringToZp(123+"name"));System.out.println(Util.hashFromStringToZp(123+"name"));System.out.println(Util.hashFromStringToZp(111+"name"));}
}
关于JPBC的密码学实现参考：
https://blog.csdn.net/zhangwenjiezw886/article/details/51006774
https://blog.csdn.net/liuweiran900217/article/details/23414629
https://blog.csdn.net/qifuchenluo/article/details/45100851
http://gas.dia.unisa.it/projects/jpbc/java-docs/api/index.html
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