KB universal accumulator

Signed-off-by: lovesh <lovesh.bond@gmail.com>

Author: lovesh

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@docknetwork/crypto-wasm-ts",
-  "version": "0.56.0",
+  "version": "0.57.0",
   "description": "Typescript abstractions over Dock's Rust crypto library's WASM wrapper",
   "homepage": "https://github.com/docknetwork/crypto-wasm-ts",
   "main": "lib/index.js",
@@ -31,7 +31,7 @@
     "@types/flat": "^5.0.2",
     "@types/lodash": "^4.14.195",
     "bs58": "5.0.0",
-    "crypto-wasm-new": "npm:@docknetwork/crypto-wasm@0.25.0",
+    "crypto-wasm-new": "npm:@docknetwork/crypto-wasm@0.26.0",
     "crypto-wasm-old": "npm:@docknetwork/crypto-wasm@0.23.0",
     "flat": "^5.0.2",
     "json-pointer": "^0.6.2",

src/accumulator/IAccumulatorState.ts

@@ -20,3 +20,17 @@ export interface IAccumulatorState {
 export interface IUniversalAccumulatorState extends IAccumulatorState {
   elements(): Promise<Iterable<Uint8Array>>;
 }
+
+export interface IKBUniversalAccumulatorState extends IAccumulatorState {
+  /**
+   * Whether this element is in the domain (could be a member or not)
+   * @param element
+   */
+  inDomain(element: Uint8Array): Promise<boolean>;
+
+  /**
+   * Takes an element not in the domain and adds it.
+   * @param element
+   */
+  addToDomain(element: Uint8Array): Promise<void>;
+}

src/accumulator/accumulator.ts

@@ -30,7 +30,7 @@ import {
   universalAccumulatorVerifyMembership,
   universalAccumulatorVerifyNonMembership
 } from 'crypto-wasm-new';
-import { VBMembershipWitness, VBNonMembershipWitness } from './accumulatorWitness';
+import { AccumulatorWitness, VBMembershipWitness, VBNonMembershipWitness } from './accumulatorWitness';
 import { getUint8ArraysFromObject } from '../util';
 import { IAccumulatorState, IUniversalAccumulatorState } from './IAccumulatorState';
 import { IInitialElementsStore } from './IInitialElementsStore';
@@ -53,7 +53,7 @@ import {
  * the state object is to check if duplicate elements are not added or already absent elements are not removed or membership witness
  * for absent elements is not created. If checks in the `state` fail, they throw errors.
  */
-export abstract class Accumulator {
+export abstract class Accumulator<T> {
   value: Uint8Array | object;
   secretKey: AccumulatorSecretKey | undefined;
   params: AccumulatorParams | undefined;
@@ -194,7 +194,7 @@ export abstract class Accumulator {
   /**
    * Get the accumulated value.
    */
-  abstract get accumulated(): Uint8Array;
+  abstract get accumulated(): T;
 
   // The following functions optionally take secret key as an argument as its better to not store secret key in memory for
   // long time.
@@ -261,7 +261,7 @@ export abstract class Accumulator {
     element: Uint8Array,
     secretKey?: AccumulatorSecretKey,
     state?: IAccumulatorState
-  ): Promise<VBMembershipWitness>;
+  ): Promise<AccumulatorWitness<T>>;
 
   /**
    * Calculate the membership witnesses for the given batch of elements
@@ -273,7 +273,7 @@ export abstract class Accumulator {
     elements: Uint8Array[],
     secretKey?: AccumulatorSecretKey,
     state?: IAccumulatorState
-  ): Promise<VBMembershipWitness[]>;
+  ): Promise<AccumulatorWitness<T>[]>;
 
   /**
    * Verify the membership witness.
@@ -284,7 +284,7 @@ export abstract class Accumulator {
    */
   abstract verifyMembershipWitness(
     member: Uint8Array,
-    witness: VBMembershipWitness,
+    witness: AccumulatorWitness<T>,
     pk: AccumulatorPublicKey,
     params?: AccumulatorParams
   ): boolean;
@@ -401,9 +401,9 @@ export abstract class Accumulator {
 }
 
 /**
- * Accumulator that supports only membership proofs.
+ * VB accumulator that supports only membership proofs.
  */
-export class PositiveAccumulator extends Accumulator {
+export class PositiveAccumulator extends Accumulator<Uint8Array> {
   // @ts-ignore
   value: Uint8Array;
 
@@ -441,7 +441,7 @@ export class PositiveAccumulator extends Accumulator {
    * Remove a single element from the accumulator
    * @param element
    * @param secretKey
-   * @param state- Optional. If provided, checked before removing and element is removed
+   * @param state Optional. If provided, checked before removing and element is removed
    */
   async remove(element: Uint8Array, secretKey?: AccumulatorSecretKey, state?: IAccumulatorState) {
     await this.ensurePresence(element, state);
@@ -576,12 +576,12 @@ export class PositiveAccumulator extends Accumulator {
 }
 
 /**
- * Accumulator that supports both membership proofs and non-membership proofs. For guarding against forgery of
+ * VB accumulator that supports both membership proofs and non-membership proofs. For guarding against forgery of
  * non-membership proofs (details in the paper), during initialization, it should generate several accumulator members
  * and never remove them from accumulator, nor it should allow duplicates of them to be added. Thus, several methods
  * accept an optional persistent database `IInitialElementsStore` which stores those initial elements.
  */
-export class UniversalAccumulator extends Accumulator {
+export class UniversalAccumulator extends Accumulator<Uint8Array> {
   /**
    * `f_V` is supposed to kept private by the accumulator manager. `V` is the accumulated value.
    */

src/accumulator/accumulatorWitness.ts

@@ -1,5 +1,4 @@
 import {
-  publicInfoForWitnessUpdate,
   updateMembershipWitnessesPostBatchUpdates,
   updateMembershipWitnessPostAdd,
   updateMembershipWitnessPostRemove,
@@ -11,34 +10,34 @@ import {
   updateNonMembershipWitnessUsingPublicInfoAfterBatchUpdate,
   updateNonMembershipWitnessUsingPublicInfoAfterMultipleBatchUpdates
 } from 'crypto-wasm-new';
-import { getUint8ArraysFromObject, jsonObjToUint8Array } from '../util';
+import { getUint8ArraysFromObject } from '../util';
 import { AccumulatorSecretKey } from './params-and-keys';
-import { BytearrayWrapper } from '../bytearray-wrapper';
+import { VBWitnessUpdateInfo, WitnessUpdateInfo } from './witness-update-info';
 
-export abstract class AccumulatorWitness {
+export abstract class AccumulatorWitness<V> {
   value: Uint8Array | object;
 
   constructor(value: Uint8Array | object) {
     this.value = value;
   }
 
-  abstract updatePostAdd(addition: Uint8Array, element: Uint8Array, accumulatorValueBeforeAddition: Uint8Array): void;
-  abstract updatePostRemove(removal: Uint8Array, element: Uint8Array, accumulatorValueAfterRemoval: Uint8Array): void;
+  abstract updatePostAdd(addition: Uint8Array, element: Uint8Array, accumulatorValueBeforeAddition: V): void;
+  abstract updatePostRemove(removal: Uint8Array, element: Uint8Array, accumulatorValueAfterRemoval: V): void;
   abstract updateUsingPublicInfoPostBatchUpdate(
     element: Uint8Array,
     additions: Uint8Array[],
     removals: Uint8Array[],
-    publicInfo: VBWitnessUpdatePublicInfo
+    publicInfo: WitnessUpdateInfo
   ): void;
   abstract updateUsingPublicInfoPostMultipleBatchUpdates(
     element: Uint8Array,
     additions: Uint8Array[][],
     removals: Uint8Array[][],
-    publicInfo: VBWitnessUpdatePublicInfo[]
+    publicInfo: WitnessUpdateInfo[]
   ): void;
 }
 
-export class VBMembershipWitness extends AccumulatorWitness {
+export class VBMembershipWitness extends AccumulatorWitness<Uint8Array> {
   // @ts-ignore
   value: Uint8Array;
 
@@ -73,7 +72,7 @@ export class VBMembershipWitness extends AccumulatorWitness {
     member: Uint8Array,
     additions: Uint8Array[],
     removals: Uint8Array[],
-    publicInfo: VBWitnessUpdatePublicInfo
+    publicInfo: VBWitnessUpdateInfo
   ) {
     this.value = updateMembershipWitnessUsingPublicInfoAfterBatchUpdate(
       this.value,
@@ -96,7 +95,7 @@ export class VBMembershipWitness extends AccumulatorWitness {
     member: Uint8Array,
     additions: Uint8Array[][],
     removals: Uint8Array[][],
-    publicInfo: VBWitnessUpdatePublicInfo[]
+    publicInfo: VBWitnessUpdateInfo[]
   ) {
     const info = publicInfo.map((i) => i.value);
     this.value = updateMembershipWitnessUsingPublicInfoAfterMultipleBatchUpdates(
@@ -149,7 +148,7 @@ export class VBMembershipWitness extends AccumulatorWitness {
   }
 }
 
-export class VBNonMembershipWitness extends AccumulatorWitness {
+export class VBNonMembershipWitness extends AccumulatorWitness<Uint8Array> {
   // @ts-ignore
   value: { d: Uint8Array; C: Uint8Array };
 
@@ -184,7 +183,7 @@ export class VBNonMembershipWitness extends AccumulatorWitness {
     nonMember: Uint8Array,
     additions: Uint8Array[],
     removals: Uint8Array[],
-    publicInfo: VBWitnessUpdatePublicInfo
+    publicInfo: VBWitnessUpdateInfo
   ) {
     this.value = updateNonMembershipWitnessUsingPublicInfoAfterBatchUpdate(
       this.value,
@@ -207,7 +206,7 @@ export class VBNonMembershipWitness extends AccumulatorWitness {
     nonMember: Uint8Array,
     additions: Uint8Array[][],
     removals: Uint8Array[][],
-    publicInfo: VBWitnessUpdatePublicInfo[]
+    publicInfo: VBWitnessUpdateInfo[]
   ) {
     const info = publicInfo.map((i) => i.value);
     this.value = updateNonMembershipWitnessUsingPublicInfoAfterMultipleBatchUpdates(
@@ -259,35 +258,3 @@ export class VBNonMembershipWitness extends AccumulatorWitness {
     return new VBNonMembershipWitness({ d, C });
   }
 }
-
-/**
- * Public info published by the accumulator manager used to update witnesses after several additions and removals.
- */
-export class VBWitnessUpdatePublicInfo extends BytearrayWrapper {
-  toJSON(): string {
-    return JSON.stringify({
-      value: this.value
-    });
-  }
-
-  fromJSON(json: string): VBWitnessUpdatePublicInfo {
-    return new VBWitnessUpdatePublicInfo(jsonObjToUint8Array(json));
-  }
-
-  /**
-   * Accumulator manager creates the witness update info corresponding to the additions and removals.
-   * @param accumulatorValueBeforeUpdates - accumulator value before the additions and removals
-   * @param additions
-   * @param removals
-   * @param sk
-   */
-  static new(
-    accumulatorValueBeforeUpdates: Uint8Array,
-    additions: Uint8Array[],
-    removals: Uint8Array[],
-    sk: AccumulatorSecretKey
-  ): VBWitnessUpdatePublicInfo {
-    const value = publicInfoForWitnessUpdate(accumulatorValueBeforeUpdates, additions, removals, sk.value);
-    return new VBWitnessUpdatePublicInfo(value);
-  }
-}

src/accumulator/in-memory-persistence.ts

@@ -1,4 +1,4 @@
-import { IAccumulatorState, IUniversalAccumulatorState } from './IAccumulatorState';
+import { IAccumulatorState, IKBUniversalAccumulatorState, IUniversalAccumulatorState } from './IAccumulatorState';
 import { IInitialElementsStore } from './IInitialElementsStore';
 
 /**
@@ -11,6 +11,10 @@ export class InMemoryState implements IAccumulatorState {
     this.state = new Set<string>();
   }
 
+  get size(): number {
+    return this.state.size;
+  }
+
   async add(element: Uint8Array): Promise<void> {
     const key = InMemoryState.key(element);
     if (this.state.has(key)) {
@@ -75,3 +79,69 @@ export class InMemoryInitialElementsStore implements IInitialElementsStore {
     return JSON.stringify(Array.from(element));
   }
 }
+
+/**
+ * In memory implementation of the state. For testing only
+ */
+export class InMemoryKBUniversalState implements IKBUniversalAccumulatorState {
+  memState: Set<string>;
+  nonMemState: Set<string>;
+
+  constructor() {
+    this.memState = new Set<string>();
+    this.nonMemState = new Set<string>();
+  }
+
+  get size(): number {
+    return this.memState.size;
+  }
+
+  add(element: Uint8Array): Promise<void> {
+    const key = InMemoryKBUniversalState.key(element);
+    if (this.memState.has(key)) {
+      throw new Error(`${element} already present in mem state`);
+    }
+    if (!this.nonMemState.has(key)) {
+      throw new Error(`${element} not present in non mem state`);
+    }
+    this.memState.add(key);
+    this.nonMemState.delete(key);
+    return Promise.resolve();
+  }
+
+  has(element: Uint8Array): Promise<boolean> {
+    const key = InMemoryKBUniversalState.key(element);
+    // Ideally, something present in `memState` should not be present in `nonMemState` and vice-versa
+    const b = this.memState.has(key) && !this.nonMemState.has(key);
+    return Promise.resolve(b);
+  }
+
+  remove(element: Uint8Array): Promise<void> {
+    const key = InMemoryKBUniversalState.key(element);
+    if (!this.memState.has(key)) {
+      throw new Error(`${element} not present in mem state`);
+    }
+    if (this.nonMemState.has(key)) {
+      throw new Error(`${element} already present in non mem state`);
+    }
+    this.memState.delete(key);
+    this.nonMemState.add(key);
+    return Promise.resolve();
+  }
+
+  static key(element: Uint8Array) {
+    return JSON.stringify(Array.from(element));
+  }
+
+  inDomain(element: Uint8Array): Promise<boolean> {
+    const key = InMemoryKBUniversalState.key(element);
+    const b = this.nonMemState.has(key) || this.memState.has(key);
+    return Promise.resolve(b);
+  }
+
+  async addToDomain(element: Uint8Array) {
+    const key = InMemoryKBUniversalState.key(element);
+    this.nonMemState.add(key);
+    return Promise.resolve();
+  }
+}

src/accumulator/index.ts

@@ -4,3 +4,4 @@ export * from './accumulatorWitness';
 export * from './proof';
 export * from './IAccumulatorState';
 export * from './IInitialElementsStore';
+export { VBWitnessUpdateInfo } from './witness-update-info';