Make more classes package-private

README.md

@@ -2,8 +2,8 @@
 ## Math
 
 The Cryptimeleon Math library provides the mathematical foundation for the other Cryptimeleon libraries.
-It provides basics such as mathematical groups, rings and fields, e.g. Zn, as well as implementations of cryptographic pairings.
-Furthermore, it provides serialization support for the implemented structures.
+It implements basics such as mathematical groups, rings and fields, e.g. Zn, as well as implementations of cryptographic pairings.
+Furthermore, it offers serialization support for the implemented structures.
 
 ## Security Disclaimer
 **WARNING: This library is meant to be used for prototyping and as a research tool *only*. It has not been sufficiently vetted for use in security-critical production environments. All implementations are to be considered experimental.**

src/main/java/org/cryptimeleon/math/serialization/RepresentableRepresentation.java

@@ -2,6 +2,7 @@
 
 import org.cryptimeleon.math.serialization.converter.JSONConverter;
 
+import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 
 /**
@@ -67,12 +68,18 @@ public Object recreateRepresentable() {
                 if (c.isEnum()) {
                     return Enum.valueOf((Class<? extends Enum>) c, representation.str().get());
                 }
-                return c.getConstructor(Representation.class).newInstance(representation);
-            } catch (NoSuchMethodException e) { //no constructor with single Representation paramenter
-                if (representation == null) //no representation necessary. Try default constructor
-                    return c.getConstructor(new Class<?>[]{}).newInstance();
-                else
+                Constructor<?> constructor = c.getConstructor(Representation.class);
+                constructor.setAccessible(true);
+                return constructor.newInstance(representation);
+            } catch (NoSuchMethodException e) { //no constructor with single Representation parameter
+                if (representation == null)  {
+                    // no representation necessary. Try default constructor
+                    Constructor<?> constructor = c.getConstructor(new Class<?>[]{});
+                    constructor.setAccessible(true);
+                    return constructor.newInstance();
+                } else {
                     throw e;
+                }
             }
         } catch (ClassNotFoundException e) {
             throw new IllegalArgumentException("Cannot find class " + representedTypeName, e);

src/main/java/org/cryptimeleon/math/serialization/annotations/internal/ArrayRepresentationHandler.java → src/main/java/org/cryptimeleon/math/serialization/annotations/ArrayRepresentationHandler.java

@@ -1,8 +1,7 @@
-package org.cryptimeleon.math.serialization.annotations.internal;
+package org.cryptimeleon.math.serialization.annotations;
 
 import org.cryptimeleon.math.serialization.ListRepresentation;
 import org.cryptimeleon.math.serialization.Representation;
-import org.cryptimeleon.math.serialization.annotations.RepresentationRestorer;
 
 import java.lang.reflect.Array;
 import java.lang.reflect.Type;
@@ -11,7 +10,7 @@
 /**
  * A handler for serializing/deserializing arrays.
  */
-public class ArrayRepresentationHandler implements RepresentationHandler {
+class ArrayRepresentationHandler implements RepresentationHandler {
     /**
      * Handler for the array elements.
      */

src/main/java/org/cryptimeleon/math/serialization/annotations/internal/DependentRepresentationHandler.java → src/main/java/org/cryptimeleon/math/serialization/annotations/DependentRepresentationHandler.java

@@ -1,16 +1,15 @@
-package org.cryptimeleon.math.serialization.annotations.internal;
+package org.cryptimeleon.math.serialization.annotations;
 
 import org.cryptimeleon.math.serialization.Representable;
 import org.cryptimeleon.math.serialization.Representation;
-import org.cryptimeleon.math.serialization.annotations.RepresentationRestorer;
 
 import java.lang.reflect.Type;
 import java.util.function.Function;
 
 /**
  * Handles representations that depend on some {@link RepresentationRestorer} in order to be recreated.
  */
-public class DependentRepresentationHandler implements RepresentationHandler {
+class DependentRepresentationHandler implements RepresentationHandler {
     /**
      * Restorer string indicating the {@code RepresentationRestorer} to use.
      */

src/main/java/org/cryptimeleon/math/serialization/annotations/internal/ListAndSetRepresentationHandler.java → src/main/java/org/cryptimeleon/math/serialization/annotations/ListAndSetRepresentationHandler.java

@@ -1,8 +1,7 @@
-package org.cryptimeleon.math.serialization.annotations.internal;
+package org.cryptimeleon.math.serialization.annotations;
 
 import org.cryptimeleon.math.serialization.ListRepresentation;
 import org.cryptimeleon.math.serialization.Representation;
-import org.cryptimeleon.math.serialization.annotations.RepresentationRestorer;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.ParameterizedType;
@@ -13,7 +12,7 @@
 /**
  * A handler for serializing/deserializing {@link List} and {@link Set} instances.
  */
-public class ListAndSetRepresentationHandler implements RepresentationHandler {
+class ListAndSetRepresentationHandler implements RepresentationHandler {
     private static final Class<?>[] supportedFallbackClasses = new Class[] {ArrayList.class, HashSet.class};
 
     /**

src/main/java/org/cryptimeleon/math/serialization/annotations/internal/MapRepresentationHandler.java → src/main/java/org/cryptimeleon/math/serialization/annotations/MapRepresentationHandler.java

@@ -1,8 +1,7 @@
-package org.cryptimeleon.math.serialization.annotations.internal;
+package org.cryptimeleon.math.serialization.annotations;
 
 import org.cryptimeleon.math.serialization.MapRepresentation;
 import org.cryptimeleon.math.serialization.Representation;
-import org.cryptimeleon.math.serialization.annotations.RepresentationRestorer;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.ParameterizedType;
@@ -14,7 +13,7 @@
 /**
  * A handler for serializing/deserializing {@link Map} instances.
  */
-public class MapRepresentationHandler implements RepresentationHandler {
+class MapRepresentationHandler implements RepresentationHandler {
     /**
      * Handler for the map's keys.
      */

src/main/java/org/cryptimeleon/math/serialization/annotations/ReprUtil.java

@@ -2,7 +2,6 @@
 
 import org.cryptimeleon.math.serialization.ObjectRepresentation;
 import org.cryptimeleon.math.serialization.Representation;
-import org.cryptimeleon.math.serialization.annotations.internal.*;
 import org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup;
 import org.cryptimeleon.math.structures.groups.elliptic.BilinearMap;
 

src/main/java/org/cryptimeleon/math/serialization/annotations/internal/RepresentationHandler.java → src/main/java/org/cryptimeleon/math/serialization/annotations/RepresentationHandler.java

@@ -1,4 +1,4 @@
-package org.cryptimeleon.math.serialization.annotations.internal;
+package org.cryptimeleon.math.serialization.annotations;
 
 import org.cryptimeleon.math.serialization.Representation;
 import org.cryptimeleon.math.serialization.annotations.RepresentationRestorer;
@@ -8,7 +8,7 @@
 /**
  * Interface for classes that can serialize and deserialize specific types of objects.
  */
-public interface RepresentationHandler {
+interface RepresentationHandler {
     /**
      * Deserializes the given representation using the given representation restorers.
      * @param repr the representation to deserialize

src/main/java/org/cryptimeleon/math/serialization/annotations/internal/StandaloneRepresentationHandler.java → src/main/java/org/cryptimeleon/math/serialization/annotations/StandaloneRepresentationHandler.java

@@ -1,7 +1,6 @@
-package org.cryptimeleon.math.serialization.annotations.internal;
+package org.cryptimeleon.math.serialization.annotations;
 
 import org.cryptimeleon.math.serialization.*;
-import org.cryptimeleon.math.serialization.annotations.RepresentationRestorer;
 
 import java.lang.reflect.Type;
 import java.math.BigInteger;
@@ -11,7 +10,7 @@
  * Handles serialization/deserialization of the representation of {@link StandaloneRepresentable} implementers
  * and some other simple types.
  */
-public class StandaloneRepresentationHandler implements RepresentationHandler {
+class StandaloneRepresentationHandler implements RepresentationHandler {
 
     // it may be temping to add int.class etc. here, but it doesn't work because the ReprUtil assumes that everything
     // that's not null is already set (and int is auto-initialized with 0)

src/main/java/org/cryptimeleon/math/structures/groups/GroupElementImpl.java

@@ -6,9 +6,8 @@
 import java.math.BigInteger;
 
 /**
- * Immutable objects representing elements of a group.
- * <p>
- * Usually wrapped by a {@link GroupElement} to offer additional evaluation capabilities.
+ * Immutable objects representing elements of a group usually wrapped by a {@link GroupElement} to offer
+ * additional evaluation capabilities.
  * <p>
  * Implementations must properly implement {@code equals()} and {@code hashCode()}.
  */

src/main/java/org/cryptimeleon/math/structures/groups/GroupImpl.java

@@ -13,9 +13,11 @@
 import java.util.Optional;
 
 /**
- * A Group. Operations are defined on its elements.
- * <p>
- * Usually wrapped by a {@link Group} to offer additional evaluation capabilities.
+ * An algebraic group implementation which can be wrapped by a {@link Group} to offer additional evaluation capabilities.
+ * Operations are defined on its elements.
+ *
+ * @see Group for the wrapper class
+ * @see GroupElementImpl for the element class
  */
 public interface GroupImpl extends StandaloneRepresentable, RepresentationRestorer {
     /**

src/main/java/org/cryptimeleon/math/structures/groups/RingAdditiveGroupImpl.java

@@ -11,7 +11,7 @@
 /**
  * Allows interpreting a ring as its additive group.
  */
-public class RingAdditiveGroupImpl extends RingGroupImpl {
+class RingAdditiveGroupImpl extends RingGroupImpl {
 
     /**
      * Instantiates this ring additive group.
@@ -37,9 +37,7 @@ public boolean hasPrimeSize() {
 
     @Override
     public double estimateCostInvPerOp() {
-        // Does not really work here since the numbers depend on the exact ring
-        // Used Zn(2^128) here
-        return 1;
+        return ring.estimateCostNegPerOp();
     }
 
     @Override

src/main/java/org/cryptimeleon/math/structures/groups/RingGroup.java

@@ -7,7 +7,7 @@
 import org.cryptimeleon.math.structures.rings.RingElement;
 
 /**
- * Represents a group instantiated from either the additive or unit groups from a ring.
+ * Represents a group instantiated from either the additive or unit group of a ring.
  */
 public class RingGroup extends BasicGroup {
     protected RingGroup(GroupImpl impl) {

src/main/java/org/cryptimeleon/math/structures/groups/RingGroupImpl.java

@@ -8,7 +8,7 @@
 /**
  * Common base class for ring subgroups (additive/unit groups).
  */
-public abstract class RingGroupImpl implements GroupImpl {
+abstract class RingGroupImpl implements GroupImpl {
     protected final Ring ring;
 
     /**

src/main/java/org/cryptimeleon/math/structures/groups/RingUnitGroupImpl.java

@@ -15,7 +15,7 @@
  * The unit group consists of the set of elements with a multiplicative inverse.
  * The group operation is multiplication and the neutral element is called the one element.
  */
-public class RingUnitGroupImpl extends RingGroupImpl {
+class RingUnitGroupImpl extends RingGroupImpl {
     public RingUnitGroupImpl(Ring ring) {
         super(ring);
     }
@@ -41,9 +41,7 @@ public boolean hasPrimeSize() {
 
     @Override
     public double estimateCostInvPerOp() {
-        // Does not really work here since the numbers depend on the exact ring
-        // Used Zn(2^128) here
-        return 0.1;
+        return ring.estimateCostInvPerOp();
     }
 
     @Override

src/main/java/org/cryptimeleon/math/structures/groups/debug/DebugGroup.java

@@ -5,7 +5,6 @@
 import org.cryptimeleon.math.serialization.annotations.Represented;
 import org.cryptimeleon.math.structures.groups.Group;
 import org.cryptimeleon.math.structures.groups.GroupElement;
-import org.cryptimeleon.math.structures.groups.lazy.ConstLazyGroupElement;
 import org.cryptimeleon.math.structures.groups.lazy.LazyGroup;
 import org.cryptimeleon.math.structures.groups.lazy.LazyGroupElement;
 import org.cryptimeleon.math.structures.rings.zn.Zn;
@@ -104,8 +103,8 @@ public GroupElement restoreElement(Representation repr) {
     public DebugGroupElement wrap(Zn.ZnElement elem) {
         return new DebugGroupElement(
                 this,
-                new ConstLazyGroupElement(groupTotal, ((DebugGroupImpl) groupTotal.getImpl()).wrap(elem)),
-                new ConstLazyGroupElement(groupExpMultiExp, ((DebugGroupImpl) groupExpMultiExp.getImpl()).wrap(elem))
+                groupTotal.wrap(((DebugGroupImpl) groupTotal.getImpl()).wrap(elem)),
+                groupExpMultiExp.wrap(((DebugGroupImpl) groupExpMultiExp.getImpl()).wrap(elem))
         );
     }
 

src/main/java/org/cryptimeleon/math/structures/groups/debug/package-info.java

@@ -1,5 +1,8 @@
 /**
  * Contains an implementation of a fast, but insecure, bilinear pairing.
  * Also allows for counting group operations and pairings.
+ * <p>
+ * The non-impl classes should be preferred unless you specifically need the impl class,
+ * e.g. for testing a specific {@link org.cryptimeleon.math.structures.groups.Group}.
  */
 package org.cryptimeleon.math.structures.groups.debug;

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/AbstractPairing.java

@@ -1,8 +1,5 @@
 package org.cryptimeleon.math.structures.groups.elliptic;
 
-import org.cryptimeleon.math.serialization.ObjectRepresentation;
-import org.cryptimeleon.math.serialization.RepresentableRepresentation;
-import org.cryptimeleon.math.serialization.Representation;
 import org.cryptimeleon.math.structures.groups.GroupElementImpl;
 import org.cryptimeleon.math.structures.rings.FieldElement;
 import org.cryptimeleon.math.structures.rings.extfield.ExtensionField;

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/nopairing/Secp256k1.java

@@ -165,7 +165,7 @@ public int hashCode() {
     }
 
     /**
-     * A hash function mapping bit strings into the group such that
+     * A hash function mapping bit strings into Secp256k1.
      */
     public static class HashIntoSecp256k1 implements HashIntoGroupImpl {
         private final HashIntoZp hash;

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularBasicBilinearGroup.java

@@ -0,0 +1,20 @@
+package org.cryptimeleon.math.structures.groups.elliptic.type1.supersingular;
+
+import org.cryptimeleon.math.serialization.Representation;
+import org.cryptimeleon.math.structures.groups.basic.BasicBilinearGroup;
+
+/**
+ * A type 1 supersingular bilinear group where operations are evaluated naively, that is, not lazily.
+ *
+ * @see SupersingularBilinearGroup for the version with lazy evaluation
+ */
+public class SupersingularBasicBilinearGroup extends BasicBilinearGroup {
+
+    public SupersingularBasicBilinearGroup(int securityParameter) {
+        super(new SupersingularTateGroupImpl(securityParameter));
+    }
+
+    public SupersingularBasicBilinearGroup(Representation repr) {
+        super(repr);
+    }
+}

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularBilinearGroup.java

@@ -4,11 +4,12 @@
 import org.cryptimeleon.math.structures.groups.lazy.LazyBilinearGroup;
 
 /**
- * Offers a less verbose way to instantiate a Supersingular bilinear group which uses lazy evaluation.
+ * A type 1 supersingular bilinear group where operations are evaluated lazily.
  * <p>
- * Essentially just a {@link LazyBilinearGroup} wrapper around {@link SupersingularTateGroupImpl}.
+ * Due to lazy evaluation, this group is more efficient than its non-lazy counterpart
+ * {@link SupersingularBasicBilinearGroup}.
  *
- * @see SupersingularTateGroupImpl
+ * @see SupersingularBasicBilinearGroup for the version without lazy evaluation
  */
 public class SupersingularBilinearGroup extends LazyBilinearGroup {
 

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularSourceGroupElementImpl.java

@@ -8,7 +8,7 @@
  *
  * @see SupersingularSourceGroupImpl
  */
-public class SupersingularSourceGroupElementImpl extends PairingSourceGroupElement {
+class SupersingularSourceGroupElementImpl extends PairingSourceGroupElement {
 
     public SupersingularSourceGroupElementImpl(SupersingularSourceGroupImpl curve, FieldElement x, FieldElement y) {
         super(curve, x, y);

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularSourceGroupImpl.java

@@ -17,7 +17,7 @@
  * Let \(E := {(x,y) \in \mathbb{F}_q \times \mathbb{F}_q | y^2 = x^3 - 3x}\) (\(q\) prime and \(q = 3 \mod 4\)).
  * Then this class represents E[getSize()], i.e. the subgroup of size getSize().
  */
-public class SupersingularSourceGroupImpl extends PairingSourceGroupImpl {
+class SupersingularSourceGroupImpl extends PairingSourceGroupImpl {
 
     /**
      * Instantiates the group.

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularSourceHash.java

@@ -9,7 +9,7 @@
 import org.cryptimeleon.math.structures.rings.extfield.ExtensionFieldElement;
 import org.cryptimeleon.math.structures.rings.zn.HashIntoZn;
 
-public class SupersingularSourceHash implements HashIntoGroupImpl {
+class SupersingularSourceHash implements HashIntoGroupImpl {
     private SupersingularSourceGroupImpl codomain;
 
     public SupersingularSourceHash(SupersingularSourceGroupImpl codomain) {

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularTargetGroupElementImpl.java

@@ -7,7 +7,7 @@
 /**
  * @see PairingTargetGroupElementImpl
  */
-public class SupersingularTargetGroupElementImpl extends PairingTargetGroupElementImpl {
+class SupersingularTargetGroupElementImpl extends PairingTargetGroupElementImpl {
 
     public SupersingularTargetGroupElementImpl(PairingTargetGroupImpl g, ExtensionFieldElement fe) {
         super(g, fe);

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularTargetGroupImpl.java

@@ -11,7 +11,7 @@
 /**
  * @see PairingTargetGroupImpl
  */
-public class SupersingularTargetGroupImpl extends PairingTargetGroupImpl {
+class SupersingularTargetGroupImpl extends PairingTargetGroupImpl {
 
     public SupersingularTargetGroupImpl(ExtensionField f, BigInteger size) {
         super(f, size);

src/main/java/org/cryptimeleon/math/structures/groups/elliptic/type1/supersingular/SupersingularTateGroupImpl.java

@@ -20,7 +20,7 @@
 /**
  * The implementation of our supersingular bilinear group.
  */
-public class SupersingularTateGroupImpl implements BilinearGroupImpl {
+class SupersingularTateGroupImpl implements BilinearGroupImpl {
 
     @Represented
     private Integer securityParameter;