KP-ABE算法java实现
时间: 2023-11-25 17:51:21 浏览: 78
以下是KP-ABE算法的Java实现示例:
```java
import it.unisa.dia.gas.jpbc.Element;
import it.unisa.dia.gas.jpbc.Pairing;
import it.unisa.dia.gas.jpbc.PairingFactory;
import it.unisa.dia.gas.jpbc.Field;
import it.unisa.dia.gas.jpbc.Field.ElementPowPreProcessing;
import it.unisa.dia.gas.plaf.jpbc.pairing.a.TypeACurveGenerator;
import it.unisa.dia.gas.plaf.jpbc.pairing.parameters.PropertiesParameters;
import it.unisa.dia.gas.plaf.jpbc.pairing.parameters.PropertiesParametersGenerator;
import it.unisa.dia.gas.plaf.jpbc.util.ElementUtils;
import java.util.ArrayList;import java.util.HashMap;
import java.util.Map;
public class KPABE {
private Pairing pairing;
private Field G1, GT, Zr;
private Element g, h, f;
private Map<String, Element> D;
private Map<String, ElementPowPreProcessing> D_pre;
private Map<String, Element> D1;
private Map<String, ElementPowPreProcessing> D1_pre;
public KPABE() {
PropertiesParametersGenerator pg = new PropertiesParametersGenerator();
pg.init(new TypeACurveGenerator(3, 32));
PropertiesParameters params = pg.generate();
this.pairing = PairingFactory.getPairing(params);
this.G1 = pairing.getG1();
this.GT = pairing.getGT();
this.Zr = pairing.getZr();
this.g = G1.newRandomElement().getImmutable();
this.h = G1.newRandomElement().getImmutable();
this.f = GT.newRandomElement().getImmutable();
this.D = new HashMap<String, Element>();
this.D_pre = new HashMap<String, ElementPowPreProcessing>();
this.D1 = new HashMap<String, Element>();
this.D1_pre = new HashMap<String, ElementPowPreProcessing>();
}
public void setup(int n) {
Element alpha = Zr.newRandomElement().getImmutable();
Element beta = Zr.newRandomElement().getImmutable();
Element g_alpha = g.powZn(alpha).getImmutable();
Element h_beta = h.powZn(beta).getImmutable();
Element f_alpha = f.powZn(alpha).getImmutable();
D.put("g_alpha", g_alpha);
D_pre.put("g_alpha", G1.newElement().set(g_alpha).getImmutable().getElementPowPreProcessing());
D.put("h_beta", h_beta);
D_pre.put("h_beta", G1.newElement().set(h_beta).getImmutable().getElementPowPreProcessing());
D.put("f_alpha", f_alpha);
D_pre.put("f_alpha", GT.newElement().set(f_alpha).getImmutable().getElementPowPreProcessing());
for (int i = 1; i <= n; i++) {
Element r = Zr.newRandomElement().getImmutable();
Element g_r = g.powZn(r).getImmutable();
Element h_r = h.powZn(r).getImmutable();
D.put("g_" + i, g_r);
D_pre.put("g_" + i, G1.newElement().set(g_r).getImmutable().getElementPowPreProcessing());
D.put("h_" + i, h_r);
D_pre.put("h_" + i, G1.newElement().set(h_r).getImmutable().getElementPowPreProcessing());
Element D1_i = g_alpha.mul(h_beta).mul(g_r).getImmutable();
D1.put("D1_" + i, D1_i);
D1_pre.put("D1_" + i, G1.newElement().set(D1_i).getImmutable().getElementPowPreProcessing());
}
}
public Map<String, Element> keygen(String[] attrs) {
Map<String, Element> sk = new HashMap<String, Element>();
Element r = Zr.newRandomElement().getImmutable();
Element D2 = g.powZn(r).getImmutable();
sk.put("D2", D2);
for (String attr : attrs) {
Element r_attr = Zr.newRandomElement().getImmutable();
Element D3_attr = g.powZn(r_attr).getImmutable();
Element D4_attr = D.get("h_" + attr).powZn(r).mul(h).powZn(r_attr).getImmutable();
sk.put("D3_" + attr, D3_attr);
sk.put("D4_" + attr, D4_attr);
}
return sk;
}
public Element encrypt(String[] attrs, String message) {
Element s = Zr.newRandomElement().getImmutable();
Element C0 = f.mul(pairing.pairing(g, h.powZn(s))).getImmutable();
Element C1 = g.powZn(s).getImmutable();
ArrayList<Element> C2_list = new ArrayList<Element>();
for (String attr : attrs) {
Element C2_attr = D.get("g_" + attr).powZn(s).getImmutable();
C2_list.add(C2_attr);
}
Element C2 = ElementUtils.getProdOfElements(C2_list).getImmutable();
Element C3 = GT.newElement().setToHash(message.getBytes(), 0, message.getBytes().length).powZn(s).getImmutable();
return pairing.getGT().newElement().setToCipherText(C0, C1, C2, C3).getImmutable();
}
public Element decrypt(Map<String, Element> sk, Element ct) {
Element D2 = sk.get("D2");
ArrayList<Element> D3_list = new ArrayList<Element>();
ArrayList<Element> D4_list = new ArrayList<Element>();
for (String attr : sk.keySet()) {
if (attr.startsWith("D3_")) {
D3_list.add(sk.get(attr));
} else if (attr.startsWith("D4_")) {
D4_list.add(sk.get(attr));
}
}
Element numerator = pairing.pairing(ct.get(1), D2).getImmutable();
ArrayList<Element> denominator_list = new ArrayList<Element>();
for (int i = 0; i < D3_list.size(); i++) {
Element D3_i = D3_list.get(i);
Element D4_i = D4_list.get(i);
Element C2_i = ct.get(2).powZn(D3_i).mul(D4_i).getImmutable();
denominator_list.add(pairing.pairing(D_pre.get("h_" + i), C2_i));
}
Element denominator = ElementUtils.getProdOfElements(denominator_list).getImmutable();
return ct.get(3).mul(numerator.div(denominator)).getImmutable();
}
public static void main(String[] args) {
KPABE kpabe = new KPABE();
kpabe.setup(5);
Map<String, Element> sk = kpabe.keygen(new String[]{"1", "2", "3"});
Element ct = kpabe.encrypt(new String[]{"1", "2"}, "hello world");
Element m = kpabe.decrypt(sk, ct);
System.out.println(m);
}
}
```