public static int setupSI(
byte[] key1,
byte[] key2,
byte[] keyENC,
String[] listOfKeyword,
Multimap<String, String> lookup,
Multimap<String, String> encryptedIdToRealId)
throws InvalidKeyException, InvalidAlgorithmParameterException, NoSuchAlgorithmException,
NoSuchProviderException, NoSuchPaddingException, IOException {
int globalCounter = 0;
for (String word : listOfKeyword) {
// Computation of the keyword tag
byte[] tag1 = CryptoPrimitives.generateCmac(key1, word);
byte[] tag2 = CryptoPrimitives.generateCmac(key2, word);
// Extraction of all documents identifiers associated to the word
Collection<String> documents = lookup.get(word);
int counter = 0;
// initialize beta to be equal to zero
int beta = 1;
for (String id : documents) {
// Compute the hash of the tag alongside with the counter
byte[] hmac =
CryptoPrimitives.concat(
CryptoPrimitives.generateHmac512(
keyHMACSI,
Integer.toString(
CryptoPrimitives.getIntFromByte(
CryptoPrimitives.generateCmac(tag1, Integer.toString(counter)), 128))),
CryptoPrimitives.generateHmac512(
keyHMACSI,
Integer.toString(
CryptoPrimitives.getIntFromByte(
CryptoPrimitives.generateCmac(tag2, Integer.toString(counter)), 128))));
// Determine the needed number of bytes for the bucket
// Divide the result of the hash in three different values
int numberOfBytes = (int) Math.ceil((Math.log(bucketSize) / (Math.log(2) * 8)));
byte[] bucket = new byte[numberOfBytes];
byte[] labelAndValue = new byte[securityParameter + valueSize];
System.arraycopy(hmac, 0, bucket, 0, bucket.length);
System.arraycopy(hmac, bucket.length, labelAndValue, 0, labelAndValue.length);
if (free.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.isEmpty()) {
System.out.println("Sub-Buckets are not big enough ==> re-do the process with a new key");
System.exit(0);
}
// generate the integer which is associated to free[b]
byte[] randomBytes =
CryptoPrimitives.randomBytes(
(int)
Math.ceil(
(Math.log(
free.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.size())
/ (Math.log(2) * 8))));
int position =
CryptoPrimitives.getIntFromByte(
randomBytes,
(int)
Math.ceil(
Math.log(
free.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.size())
/ Math.log(2)));
while (position
>= free.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.size()) {
position = position / 2;
}
int valueOfSubBucket =
free.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.get(position);
free.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.remove(position);
// The last document
if (counter == documents.size() - 1) {
beta = 0;
}
byte[] label = new byte[securityParameter];
byte[] value = new byte[valueSize];
System.arraycopy(labelAndValue, 0, label, 0, label.length);
System.arraycopy(labelAndValue, label.length, value, 0, value.length);
secureIndex
.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.get(valueOfSubBucket)
.setLabel(label);
// Computation of masked value
Iterator<String> itr = encryptedIdToRealId.get(id).iterator();
byte[] identifierBytes =
CryptoPrimitives.encryptAES_CTR_String(
keyENC, CryptoPrimitives.randomBytes(16), itr.next(), 60);
byte[] identifierBF = new byte[10];
String idBF = Integer.toString(globalCounter);
while (idBF.length() < 10) {
idBF = "0" + idBF;
}
for (int h = 0; h < 10; h++) {
identifierBF[h] = (byte) idBF.charAt(h);
}
byte[] betaByte = {(byte) beta};
byte[] concatenation = CryptoPrimitives.concat(betaByte, identifierBytes);
concatenation = CryptoPrimitives.concat(concatenation, identifierBF);
int k = 0;
for (byte b : value) {
value[k] = (byte) (b ^ concatenation[k++]);
}
secureIndex
.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.get(valueOfSubBucket)
.setValue(value);
counter++;
globalCounter++;
}
}
return 1;
}
public static List<InvertedIndexResultFormat> testSI(
byte[] token1, byte[] token2, List<List<Record>> secureIndex, int bucketSize)
throws InvalidKeyException, InvalidAlgorithmParameterException, NoSuchAlgorithmException,
NoSuchProviderException, NoSuchPaddingException, IOException {
List<InvertedIndexResultFormat> result = new ArrayList<InvertedIndexResultFormat>();
// initialize beta to 1
int beta = 1;
// initialize the counter to 0
int counter = 0;
int numberOfBytes = (int) Math.ceil((Math.log(bucketSize) / (Math.log(2) * 8)));
// security parameter in bytes defines the label while the value size defines the concatenation
// of the beta, the identifier of the document and the pointer to the bloom filter
int securityParameter = 16;
int valueSize = 87;
while (beta != 0) {
// Generate the HMAC based for each identifier
byte[] hmac =
CryptoPrimitives.concat(
CryptoPrimitives.generateHmac512(
keyHMACSI,
Integer.toString(
CryptoPrimitives.getIntFromByte(
CryptoPrimitives.generateCmac(token1, Integer.toString(counter)), 128))),
CryptoPrimitives.generateHmac512(
keyHMACSI,
Integer.toString(
CryptoPrimitives.getIntFromByte(
CryptoPrimitives.generateCmac(token2, Integer.toString(counter)), 128))));
// parsing the result of the random
byte[] bucket = new byte[numberOfBytes];
byte[] label = new byte[securityParameter];
byte[] value = new byte[valueSize];
System.arraycopy(hmac, 0, bucket, 0, bucket.length);
System.arraycopy(hmac, bucket.length, label, 0, label.length);
System.arraycopy(hmac, bucket.length + label.length, value, 0, value.length);
int counterWorNotExist = 0;
boolean flag2 = false;
for (Record record :
secureIndex.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))) {
if (Arrays.equals(record.getLabel(), label)) {
flag2 = true;
// De-masking the value
int k = 0;
for (byte b : value) {
value[k] = (byte) (b ^ record.getValue()[k++]);
}
// Spliting the array "value" to FLAG + TITLE + BF IDENTIFIER
byte[] flagByte = new byte[1];
byte[] docId = new byte[76];
byte[] bFId = new byte[10];
System.arraycopy(value, 0, flagByte, 0, flagByte.length);
System.arraycopy(value, flagByte.length, docId, 0, docId.length);
System.arraycopy(value, flagByte.length + docId.length, bFId, 0, bFId.length);
// instantiation of the record encoding
String valueMatch = "";
for (int s = 0; s < value.length; s++) {
valueMatch = valueMatch + (char) value[s];
}
// checking if it is the last identifier
if (String.valueOf(flagByte[0]).charAt(0) == '0') {
beta = 0;
}
// return the string of the identifier and the bloom filter
result.add(new InvertedIndexResultFormat(docId, bFId));
} else if ((counterWorNotExist
== secureIndex
.get(
CryptoPrimitives.getIntFromByte(
bucket, (int) (Math.log(bucketSize) / (Math.log(2)))))
.size()
- 1)
&& (flag2 == false)) {
// the word searched for does not exists
beta = 0;
}
counterWorNotExist++;
}
counter++;
}
return result;
}