├── .gitignore
├── 身份基加密IBE.pdf
├── .idea
    ├── .gitignore
    ├── vcs.xml
    ├── modules.xml
    ├── misc.xml
    └── libraries
    │   └── lib.xml
├── data
    ├── msk.properties
    ├── sk.properties
    ├── ct.properties
    └── pk.properties
├── lib
    ├── jpbc-api-2.0.0 2.jar
    └── jpbc-plaf-2.0.0 2.jar
├── a.properties
├── IBE.iml
├── README.md
└── src
    ├── JPBCDemo.java
    └── IBE.java


/.gitignore:
--------------------------------------------------------------------------------
1 | # Project exclude paths
2 | /out/


--------------------------------------------------------------------------------
/身份基加密IBE.pdf:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/hjlpb/IBE/HEAD/身份基加密IBE.pdf


--------------------------------------------------------------------------------
/.idea/.gitignore:
--------------------------------------------------------------------------------
1 | # Default ignored files
2 | /shelf/
3 | /workspace.xml
4 | 


--------------------------------------------------------------------------------
/data/msk.properties:
--------------------------------------------------------------------------------
1 | #Sun Jan 02 12:35:06 CST 2022
2 | x=WQRRYapCqPwqOG3Li+OYFuDkT7M\=
3 | 


--------------------------------------------------------------------------------
/lib/jpbc-api-2.0.0 2.jar:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/hjlpb/IBE/HEAD/lib/jpbc-api-2.0.0 2.jar


--------------------------------------------------------------------------------
/lib/jpbc-plaf-2.0.0 2.jar:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/hjlpb/IBE/HEAD/lib/jpbc-plaf-2.0.0 2.jar


--------------------------------------------------------------------------------
/.idea/vcs.xml:
--------------------------------------------------------------------------------
1 | <?xml version="1.0" encoding="UTF-8"?>
2 | <project version="4">
3 |   <component name="VcsDirectoryMappings">
4 |     <mapping directory="$PROJECT_DIR$" vcs="Git" />
5 |   </component>
6 | </project>


--------------------------------------------------------------------------------
/data/sk.properties:
--------------------------------------------------------------------------------
1 | #Sun Jan 02 12:35:06 CST 2022
2 | sk=Ltnr/83vDDeyBGZHcSYS34M6fBPY5ZS5szIkbf5nbkdfFUCLfN1O5wQBi9kEixr6GSu3+LXbQUPSc4soI+kC2guCkHpeWwzgmazuvMu4LYEjEAeGHcaI1G8/S+bcpGxuOP95eHPtfWy3etvjrsQ6e7PUtO7Nyq9TxuD7DVS73V0\=
3 | 


--------------------------------------------------------------------------------
/data/ct.properties:
--------------------------------------------------------------------------------
1 | #Sun Jan 02 12:35:06 CST 2022
2 | C1=poUrHFWTpUZ5xj1qaaMFduKz7hBfdFglEtcGUKasI/DrtsjLbk5yFvWmAJjxBN+WPgmWDiOmIOI82zXwl8fEJQKiqLKOvXxXefmk9MIbq95xT7cH8Jve0oSoIC8V9PvLs90/HoD9fIwAmjyBLehWarft5TJeUNsZ41YxJGYOOdM\=
3 | C2=H0AsGyX22S2s6Q\=\=
4 | 


--------------------------------------------------------------------------------
/.idea/modules.xml:
--------------------------------------------------------------------------------
1 | <?xml version="1.0" encoding="UTF-8"?>
2 | <project version="4">
3 |   <component name="ProjectModuleManager">
4 |     <modules>
5 |       <module fileurl="file://$PROJECT_DIR$/IBE.iml" filepath="$PROJECT_DIR$/IBE.iml" />
6 |     </modules>
7 |   </component>
8 | </project>


--------------------------------------------------------------------------------
/.idea/misc.xml:
--------------------------------------------------------------------------------
1 | <?xml version="1.0" encoding="UTF-8"?>
2 | <project version="4">
3 |   <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="17" project-jdk-type="JavaSDK">
4 |     <output url="file://$PROJECT_DIR$/out" />
5 |   </component>
6 | </project>


--------------------------------------------------------------------------------
/.idea/libraries/lib.xml:
--------------------------------------------------------------------------------
 1 | <component name="libraryTable">
 2 |   <library name="lib">
 3 |     <CLASSES>
 4 |       <root url="file://$PROJECT_DIR$/lib" />
 5 |     </CLASSES>
 6 |     <JAVADOC />
 7 |     <SOURCES />
 8 |     <jarDirectory url="file://$PROJECT_DIR$/lib" recursive="false" />
 9 |   </library>
10 | </component>


--------------------------------------------------------------------------------
/a.properties:
--------------------------------------------------------------------------------
1 | type a
2 | q 8780710799663312522437781984754049815806883199414208211028653399266475630880222957078625179422662221423155858769582317459277713367317481324925129998224791
3 | h 12016012264891146079388821366740534204802954401251311822919615131047207289359704531102844802183906537786776
4 | r 730750818665451621361119245571504901405976559617
5 | exp2 159
6 | exp1 107
7 | sign1 1
8 | sign0 1
9 | 


--------------------------------------------------------------------------------
/data/pk.properties:
--------------------------------------------------------------------------------
1 | #Sun Jan 02 12:35:06 CST 2022
2 | gx=oDhNdr+y2M+2iX1ZNH7t4lUAz8pyWpSrTCK2EShcf4wpwC8Lm1jggsO9tpZs3BwGVfl4x9qur7C2z9VtkYEV353zdAT396TIPPF/1vU6bF+FOJCKdzI1D+eTwWVSZP87xAr6cfnWFfwat2DVZxQp+qtGPnpO8FK21EWw++lNeAc\=
3 | g=eFeLVjqZ0beuz5MCdEKtbWHETw7gTOlVoj1OaO7JDllAb3vogy+o05lYa0HEvl4E6e++UvB/n/NYKbrKW4D7JU+bnpqMg/+nYpinnZn009inycaGihhyQjtywbZ+9BlO07vnuLc6mQqv8x9IW0Jo24J7lpDMWK9Ahb4uexZpD9U\=
4 | 


--------------------------------------------------------------------------------
/IBE.iml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="UTF-8"?>
 2 | <module type="JAVA_MODULE" version="4">
 3 |   <component name="NewModuleRootManager" inherit-compiler-output="true">
 4 |     <exclude-output />
 5 |     <content url="file://$MODULE_DIR$">
 6 |       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
 7 |     </content>
 8 |     <orderEntry type="inheritedJdk" />
 9 |     <orderEntry type="sourceFolder" forTests="false" />
10 |     <orderEntry type="library" name="lib" level="project" />
11 |   </component>
12 | </module>


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # 身份基加密 (Identity based Encryption)算法
 2 | 
 3 | 论文 [Identity-Based Encryption from the Weil Pairing](https://crypto.stanford.edu/~dabo/papers/bfibe.pdf)
 4 | 
 5 | ## Setup
 6 | 
 7 | 1. 生成pairing相关公共参数 $<e,G_1, G_T,Z_r>$
 8 | 2. 选取随机数$x\in Z_r$ 作为系统主密钥$msk$
 9 | 3. 选取随机元素$g\in G_1$作为生成元，计算公共参数$g^x$。因此，有系统公钥$pk=<g,g^x>$
10 | 4. 选取公共哈希函数 $H_1:\{0,1\}^*\rightarrow G_1^*$，$H_2:G_T \rightarrow \{0,1\}^n$
11 | 
12 | ## KeyGen
13 | 
14 | 1. 给定用户身份 $ID\in \{0,1\}^*$，将其映射为群$G_1$上的元素。即计算 $Q_{ID}=H_1(ID)$
15 | 2. 由系统主密钥$x$计算此$ID$对应的私钥为$sk=Q_{ID}^x$
16 | 
17 | ## Encrypt
18 | 
19 | 1. 针对目标用户身份$ID\in \{0,1\}^*$，计算 $Q_{ID}=H_1(ID)$
20 | 2. 选取随机数$r\in Z_r$，计算密文组件$C_1=g^r$ 
21 | 3. 计算$g_{ID}=e(Q_{ID},g^x)^r$
22 | 4. 计算密文组件$C_2=M \oplus H_2(g_{ID})$，其中$M \in \{0,1\}^n$是明文数据
23 | 5. 最终的密文为$<C_1,C_2>$
24 | 
25 | ## Decrypt
26 | 
27 | 1. 解密的关键在于恢复$g_{ID}$
28 | 2. $e(sk,C_1)=e(Q_{ID}^x,g^r)=e(Q_{ID},g)^{xr}=g_{ID}$
29 | 3. 恢复明文 $M=C_2 \oplus H_2(e(sk,C_1))$
30 | 
31 | 
32 | 
33 | # 代码实现
34 | 
35 | 
36 | 
37 | # 注意事项
38 | 
39 | 1. 选择用Properties保存是因为支持键值读取，比如密文可能包含多个组件，方便分别读取每个组件。
40 | 2. SetProperties的第二个参数必须为String类型，对于Zr群元素x可以调用`x.toBigInteger().toString()`
41 | 
42 | 


--------------------------------------------------------------------------------
/src/JPBCDemo.java:
--------------------------------------------------------------------------------
 1 | import it.unisa.dia.gas.jpbc.Element;
 2 | import it.unisa.dia.gas.jpbc.Field;
 3 | import it.unisa.dia.gas.jpbc.Pairing;
 4 | import it.unisa.dia.gas.plaf.jpbc.pairing.PairingFactory;
 5 | 
 6 | 
 7 | public class JPBCDemo {
 8 |     public static void main(String[] args) {
 9 |         // 一、基于特定椭圆曲线类型生成Pairing实例
10 |         // 1.从文件导入椭圆曲线参数
11 |         Pairing bp = PairingFactory.getPairing("a.properties");
12 | 
13 |         // 2.自定义曲线参数
14 |         // int rBits = 160;
15 |         // int qBits = 512;
16 |         // TypeACurveGenerator pg = new TypeACurveGenerator(rBits, qBits);
17 |         // PairingParameters pp = pg.generate();
18 |         // Pairing bp = PairingFactory.getPairing(pp);
19 | 
20 |         // 二、选择群上的元素
21 |         Field G1 = bp.getG1();
22 |         Field Zr = bp.getZr();
23 |         Element g = G1.newRandomElement().getImmutable();
24 |         Element a = Zr.newRandomElement().getImmutable();
25 |         Element b = Zr.newRandomElement().getImmutable();
26 | 
27 |         // 三、计算等式左半部分
28 |         Element ga = g.powZn(a);
29 |         Element gb = g.powZn(b);
30 |         Element egg_ab = bp.pairing(ga,gb);
31 | 
32 |         // 四、计算等式右半部分
33 |         Element egg = bp.pairing(g,g).getImmutable();
34 |         Element ab = a.mul(b);
35 |         Element egg_ab_p = egg.powZn(ab);
36 | 
37 |         if (egg_ab.isEqual(egg_ab_p)) {
38 |             System.out.println("yes");
39 |         }
40 |         else {
41 |             System.out.println("No");
42 |         }
43 |     }
44 | }
45 | 


--------------------------------------------------------------------------------
/src/IBE.java:
--------------------------------------------------------------------------------
  1 | import it.unisa.dia.gas.jpbc.Element;
  2 | import it.unisa.dia.gas.jpbc.Pairing;
  3 | import it.unisa.dia.gas.plaf.jpbc.pairing.PairingFactory;
  4 | 
  5 | import java.io.FileInputStream;
  6 | import java.io.FileOutputStream;
  7 | import java.io.IOException;
  8 | import java.security.MessageDigest;
  9 | import java.security.NoSuchAlgorithmException;
 10 | import java.util.Base64;
 11 | import java.util.Properties;
 12 | 
 13 | public class IBE {
 14 | 
 15 |     public static void setup(String pairingParametersFileName, String pkFileName, String mskFileName) {
 16 |         Pairing bp = PairingFactory.getPairing(pairingParametersFileName);
 17 | 
 18 |         Element x = bp.getZr().newRandomElement().getImmutable();
 19 |         Properties mskProp = new Properties();
 20 |         //mskProp.setProperty("x", x.toBigInteger().toString());   //x有toBigInteger方法，因此可以用这种方式，但g不能
 21 |         //后面对写的元素统一采用如下方法：首先将元素转为字节数组，然后进行Base64编码为可读字符串
 22 |         mskProp.setProperty("x", Base64.getEncoder().encodeToString(x.toBytes()));
 23 |         storePropToFile(mskProp, mskFileName);
 24 | 
 25 |         Element g = bp.getG1().newRandomElement().getImmutable();
 26 |         Element gx = g.powZn(x).getImmutable();
 27 |         Properties pkProp = new Properties();
 28 |         //pkProp.setProperty("g", new String(g.toBytes()));  //可以用这种方式将g转换为字符串后写入，但文件中显示乱码
 29 |         //为了避免乱码问题，采用Base64编码方式
 30 |         pkProp.setProperty("g", Base64.getEncoder().encodeToString(g.toBytes()));
 31 |         pkProp.setProperty("gx", Base64.getEncoder().encodeToString(gx.toBytes()));
 32 |         storePropToFile(pkProp, pkFileName);
 33 |     }
 34 | 
 35 |     public static void keygen(String pairingParametersFileName, String id, String mskFileName, String skFileName) throws NoSuchAlgorithmException {
 36 |         Pairing bp = PairingFactory.getPairing(pairingParametersFileName);
 37 | 
 38 |         byte[] idHash = sha1(id);
 39 |         Element QID = bp.getG1().newElementFromHash(idHash, 0, idHash.length).getImmutable();
 40 | 
 41 |         Properties mskProp = loadPropFromFile(mskFileName);
 42 |         String xString = mskProp.getProperty("x");
 43 | //        Element x = bp.getZr().newElement(new BigInteger(xString));  //对应于前面的x.toBigInteger().toString()方式
 44 |         Element x = bp.getZr().newElementFromBytes(Base64.getDecoder().decode(xString)).getImmutable();  //Base64编码后对应的恢复元素的方法
 45 | 
 46 |         Element sk = QID.powZn(x).getImmutable();
 47 |         Properties skProp = new Properties();
 48 |         skProp.setProperty("sk", Base64.getEncoder().encodeToString(sk.toBytes()));
 49 |         storePropToFile(skProp, skFileName);
 50 |     }
 51 | 
 52 |     public static void encrypt(String pairingParametersFileName, String message, String id, String pkFileName, String ctFileName) throws NoSuchAlgorithmException {
 53 |         Pairing bp = PairingFactory.getPairing(pairingParametersFileName);
 54 | 
 55 |         byte[] idHash = sha1(id);
 56 |         Element QID = bp.getG1().newElementFromHash(idHash, 0, idHash.length).getImmutable();
 57 | 
 58 |         Properties pkProp = loadPropFromFile(pkFileName);
 59 |         String gString = pkProp.getProperty("g");
 60 |         Element g = bp.getG1().newElementFromBytes(Base64.getDecoder().decode(gString)).getImmutable();
 61 |         String gxString = pkProp.getProperty("gx");
 62 |         Element gx = bp.getG1().newElementFromBytes(Base64.getDecoder().decode(gxString)).getImmutable();
 63 | 
 64 |         Element r = bp.getZr().newRandomElement().getImmutable();
 65 |         Element C1 = g.powZn(r).getImmutable();
 66 | 
 67 |         Element gID = bp.pairing(QID, gx).powZn(r).getImmutable();
 68 | 
 69 |         String gIDString = new String(gID.toBytes());
 70 |         byte[] HgID = sha1(gIDString);
 71 |         byte[] messageByte = message.getBytes();
 72 | 
 73 |         byte[] C2 = new byte[messageByte.length];
 74 |         //假设m明文字节长度n小于HgID的长度20，取HgID的前n个字节进行异或
 75 |         for (int i = 0; i < messageByte.length; i++){
 76 |             C2[i] = (byte)(messageByte[i] ^ HgID[i]);
 77 |         }
 78 | 
 79 |         Properties ctProp = new Properties();
 80 |         ctProp.setProperty("C1", Base64.getEncoder().encodeToString(C1.toBytes()));
 81 |         ctProp.setProperty("C2", Base64.getEncoder().encodeToString(C2));
 82 |         storePropToFile(ctProp, ctFileName);
 83 |     }
 84 | 
 85 |     public static String decrypt(String pairingParametersFileName, String ctFileName, String pkFileName, String skFileName) throws NoSuchAlgorithmException {
 86 |         Pairing bp = PairingFactory.getPairing(pairingParametersFileName);
 87 | 
 88 |         Properties skProp = loadPropFromFile(skFileName);
 89 |         String skString = skProp.getProperty("sk");
 90 |         Element sk = bp.getG1().newElementFromBytes(Base64.getDecoder().decode(skString)).getImmutable();
 91 | 
 92 |         Properties ctProp = loadPropFromFile(ctFileName);
 93 |         String C1String = ctProp.getProperty("C1");
 94 |         Element C1 = bp.getG1().newElementFromBytes(Base64.getDecoder().decode(C1String)).getImmutable();
 95 |         String C2String = ctProp.getProperty("C2");
 96 |         byte[] C2 = Base64.getDecoder().decode(C2String);
 97 | 
 98 |         Element gID = bp.pairing(sk, C1).getImmutable();
 99 | 
100 |         String gIDString = new String(gID.toBytes());
101 |         byte[] HgID = sha1(gIDString);
102 |         byte[] res = new byte[C2.length];
103 |         for (int i = 0; i < C2.length; i++){
104 |             res[i] = (byte)(C2[i] ^ HgID[i]);
105 |         }
106 |         return new String(res);
107 |     }
108 | 
109 |     public static void storePropToFile(Properties prop, String fileName){
110 |         try(FileOutputStream out = new FileOutputStream(fileName)){
111 |             prop.store(out, null);
112 |         }
113 |         catch (IOException e) {
114 |             e.printStackTrace();
115 |             System.out.println(fileName + " save failed!");
116 |             System.exit(-1);
117 |         }
118 |     }
119 | 
120 |     public static Properties loadPropFromFile(String fileName) {
121 |         Properties prop = new Properties();
122 |         try (FileInputStream in = new FileInputStream(fileName)){
123 |             prop.load(in);
124 |         }
125 |         catch (IOException e){
126 |             e.printStackTrace();
127 |             System.out.println(fileName + " load failed!");
128 |             System.exit(-1);
129 |         }
130 |         return prop;
131 |     }
132 | 
133 |     public static byte[] sha1(String content) throws NoSuchAlgorithmException {
134 |         MessageDigest instance = MessageDigest.getInstance("SHA-1");
135 |         instance.update(content.getBytes());
136 |         return instance.digest();
137 |     }
138 | 
139 |     public static void main(String[] args) throws Exception {
140 | 
141 |         String idBob = "bob@example.com";
142 |         String idAlice = "alice@example.com";
143 |         String message = "i hate you";
144 | 
145 |         String dir = "data/";
146 |         String pairingParametersFileName = "a.properties";
147 |         String pkFileName = dir + "pk.properties";
148 |         String mskFileName = dir + "msk.properties";
149 |         String skFileName = dir + "sk.properties";
150 |         String ctFileName = dir + "ct.properties";
151 | 
152 |         setup(pairingParametersFileName, pkFileName, mskFileName);
153 | 
154 |         keygen(pairingParametersFileName, idBob, mskFileName, skFileName);
155 | 
156 |         encrypt(pairingParametersFileName, message, idBob, pkFileName, ctFileName);
157 | 
158 |         String res = decrypt(pairingParametersFileName, ctFileName, pkFileName, skFileName);
159 | 
160 |         System.out.println(res);
161 |     }
162 | 
163 | }
164 | 


--------------------------------------------------------------------------------