diff --git a/.node-version b/.node-version
new file mode 100644
index 0000000..c5b7294
--- /dev/null
+++ b/.node-version
@@ -0,0 +1 @@
+11.15.0
diff --git a/package.json b/package.json
index 53e471d..76c076e 100644
--- a/package.json
+++ b/package.json
@@ -56,6 +56,7 @@
     "browserify": "^16.5.1",
     "crypto": "0.0.3",
     "ethereumjs-util": "^7.0.9",
+    "keccak256": "^1.0.6",
     "rimraf": "^2.6.3",
     "sha1": "^1.1.1",
     "standard": "^14.3.4",
diff --git a/src/MerkleTree.ts b/src/MerkleTree.ts
index b4e4bca..4643f80 100644
--- a/src/MerkleTree.ts
+++ b/src/MerkleTree.ts
@@ -3,6 +3,8 @@ import SHA256 from 'crypto-js/sha256'
 import Base from './Base'
 import treeify from 'treeify'
 
+// TODO: Clean up and DRY up code
+
 type TValue = Buffer | string | number | null | undefined
 type THashFnResult = Buffer | string
 type THashFn = (value: TValue) => Buffer
@@ -96,10 +98,10 @@ export class MerkleTree extends Base {
 
   private processLeaves (leaves: TLeaf[]) {
     if (this.hashLeaves) {
-      leaves = leaves.map(leaf => this.hashFn(leaf))
+      leaves = leaves.map(this.hashFn)
     }
 
-    this.leaves = leaves.map(leaf => this.bufferify(leaf))
+    this.leaves = leaves.map(this.bufferify)
     if (this.sortLeaves) {
       this.leaves = this.leaves.sort(Buffer.compare)
     }
@@ -193,7 +195,7 @@ export class MerkleTree extends Base {
     if (shouldHash) {
       leaf = this.hashFn(leaf)
     }
-    this.processLeaves([...this.leaves, leaf])
+    this.processLeaves(this.leaves.concat(leaf))
   }
 
   /**
@@ -208,9 +210,9 @@ export class MerkleTree extends Base {
    */
   addLeaves (leaves: TLeaf[], shouldHash: boolean = false) {
     if (shouldHash) {
-      leaves = leaves.map(leaf => this.hashFn(leaf))
+      leaves = leaves.map(this.hashFn)
     }
-    this.processLeaves([...this.leaves, ...leaves])
+    this.processLeaves(this.leaves.concat(leaves))
   }
 
   /**
@@ -225,7 +227,7 @@ export class MerkleTree extends Base {
   getLeaves (values?: any[]):Buffer[] {
     if (Array.isArray(values)) {
       if (this.hashLeaves) {
-        values = values.map(value => this.hashFn(value))
+        values = values.map(this.hashFn)
         if (this.sortLeaves) {
           values = values.sort(Buffer.compare)
         }
@@ -347,7 +349,7 @@ export class MerkleTree extends Base {
       throw new Error('Expected JSON string to be array')
     }
 
-    return parsed.map(leaf => MerkleTree.bufferify(leaf))
+    return parsed.map(MerkleTree.bufferify)
   }
 
   /**
@@ -375,7 +377,7 @@ export class MerkleTree extends Base {
   getHexLayers ():string[] {
     return this.layers.reduce((acc: string[][], item: Buffer[]) => {
       if (Array.isArray(item)) {
-        acc.push(item.map(value => this.bufferToHex(value)))
+        acc.push(item.map(layer => this.bufferToHex(layer)))
       } else {
         acc.push(item)
       }
@@ -684,6 +686,50 @@ export class MerkleTree extends Base {
     })
   }
 
+  private getProofIndicesForUnevenTree (sortedLeafIndices: number[], leavesCount: number): number[][] {
+    const depth = Math.ceil(Math.log2(leavesCount))
+    const unevenLayers :any[] = []
+    for (let index = 0; index < depth; index++) {
+      const unevenLayer = leavesCount % 2 !== 0
+      if (unevenLayer) {
+        unevenLayers.push({ index, leavesCount })
+      }
+      leavesCount = Math.ceil(leavesCount / 2)
+    }
+
+    const proofIndices: number[][] = []
+
+    let layerNodes: any[] = sortedLeafIndices
+    for (let layerIndex = 0; layerIndex < depth; layerIndex++) {
+      const siblingIndices = layerNodes.map((index: any) => {
+        if (index % 2 === 0) {
+          return index + 1
+        }
+        return index - 1
+      })
+      let proofNodeIndices = siblingIndices.filter((index: any) => !layerNodes.includes(index))
+      const unevenLayer = unevenLayers.find(({ index }) => index === layerIndex)
+      if (unevenLayer && layerNodes.includes(unevenLayer.leavesCount - 1)) {
+        proofNodeIndices = proofNodeIndices.slice(0, -1)
+      }
+
+      proofIndices.push(proofNodeIndices)
+      layerNodes = [...new Set(layerNodes.map((index: any) => {
+        if (index % 2 === 0) {
+          return index / 2
+        }
+
+        if (index % 2 === 0) {
+          return (index + 1) / 2
+        }
+
+        return (index - 1) / 2
+      }))]
+    }
+
+    return proofIndices
+  }
+
   /**
    * getMultiProof
    * @desc Returns the multiproof for given tree indices.
@@ -699,47 +745,106 @@ export class MerkleTree extends Base {
     if (!indices) {
       indices = tree
       tree = this.getLayersFlat()
+    }
 
-      if (!indices.every(Number.isInteger)) {
-        let els = indices
-        if (this.sortPairs) {
-          els = els.sort(Buffer.compare)
-        }
-
-        let ids = els.map((el) => this._bufferIndexOf(this.leaves, el)).sort((a, b) => a === b ? 0 : a > b ? 1 : -1)
-        if (!ids.every((idx) => idx !== -1)) {
-          throw new Error('Element does not exist in Merkle tree')
-        }
-
-        const hashes = []
-        const proof = []
-        let nextIds = []
-
-        for (let i = 0; i < this.layers.length; i++) {
-          const layer = this.layers[i]
-          for (let j = 0; j < ids.length; j++) {
-            const idx = ids[j]
-            const pairElement = this._getPairNode(layer, idx)
-
-            hashes.push(layer[idx])
-            if (pairElement) {
-              proof.push(pairElement)
-            }
-
-            nextIds.push((idx / 2) | 0)
-          }
-
-          ids = nextIds.filter((value, i, self) => self.indexOf(value) === i)
-          nextIds = []
-        }
-
-        return proof.filter((value) => !hashes.includes(value))
+    const isUneven = this.isUnevenTree()
+    if (isUneven) {
+      if (indices.every(Number.isInteger)) {
+        return this.getMultiProofForUnevenTree(indices)
       }
     }
 
+    if (!indices.every(Number.isInteger)) {
+      let els = indices
+      if (this.sortPairs) {
+        els = els.sort(Buffer.compare)
+      }
+
+      let ids = els.map((el) => this._bufferIndexOf(this.leaves, el)).sort((a, b) => a === b ? 0 : a > b ? 1 : -1)
+      if (!ids.every((idx) => idx !== -1)) {
+        throw new Error('Element does not exist in Merkle tree')
+      }
+
+      const hashes = []
+      const proof = []
+      let nextIds = []
+
+      for (let i = 0; i < this.layers.length; i++) {
+        const layer = this.layers[i]
+        for (let j = 0; j < ids.length; j++) {
+          const idx = ids[j]
+          const pairElement = this._getPairNode(layer, idx)
+
+          hashes.push(layer[idx])
+          if (pairElement) {
+            proof.push(pairElement)
+          }
+
+          nextIds.push((idx / 2) | 0)
+        }
+
+        ids = nextIds.filter((value, i, self) => self.indexOf(value) === i)
+        nextIds = []
+      }
+
+      return proof.filter((value) => !hashes.includes(value))
+    }
+
     return this.getProofIndices(indices, this._log2((tree.length / 2) | 0)).map(index => tree[index])
   }
 
+  private getMultiProofForUnevenTree (tree?: any[], indices?: any[]):Buffer[] {
+    if (!indices) {
+      indices = tree
+      tree = this.getLayers()
+    }
+
+    let proofHashes : Buffer[] = []
+    let currentLayerIndices: number[] = indices
+    for (const treeLayer of tree) {
+      const siblings: Buffer[] = []
+      for (const index of currentLayerIndices) {
+        if (index % 2 === 0) {
+          const idx = index + 1
+          if (!currentLayerIndices.includes(idx)) {
+            if (treeLayer[idx]) {
+              siblings.push(treeLayer[idx])
+              continue
+            }
+          }
+        }
+        const idx = index - 1
+        if (!currentLayerIndices.includes(idx)) {
+          if (treeLayer[idx]) {
+            siblings.push(treeLayer[idx])
+            continue
+          }
+        }
+      }
+
+      proofHashes = proofHashes.concat(siblings)
+      const uniqueIndices = new Set<number>()
+
+      for (const index of currentLayerIndices) {
+        if (index % 2 === 0) {
+          uniqueIndices.add(index / 2)
+          continue
+        }
+
+        if (index % 2 === 0) {
+          uniqueIndices.add((index + 1) / 2)
+          continue
+        }
+
+        uniqueIndices.add((index - 1) / 2)
+      }
+
+      currentLayerIndices = Array.from(uniqueIndices)
+    }
+
+    return proofHashes
+  }
+
   /**
    * getHexMultiProof
    * @desc Returns the multiproof for given tree indices as hex strings.
@@ -908,6 +1013,11 @@ export class MerkleTree extends Base {
    *```
    */
   verifyMultiProof (root: Buffer | string, indices: number[], leaves: Buffer[] | string[], depth: number, proof: Buffer[] | string[]):boolean {
+    const isUneven = this.isUnevenTree()
+    if (isUneven) {
+      return this.verifyMultiProofForUnevenTree(root, indices, leaves, depth, proof)
+    }
+
     root = this.bufferify(root)
     leaves = (leaves as any[]).map(leaf => this.bufferify(leaf))
     proof = (proof as any[]).map(leaf => this.bufferify(leaf))
@@ -930,7 +1040,8 @@ export class MerkleTree extends Base {
           pair = pair.sort(Buffer.compare)
         }
 
-        tree[(index / 2) | 0] = this.hashFn(Buffer.concat(pair))
+        const hash = pair[1] ? this.hashFn(Buffer.concat(pair)) : pair[0]
+        tree[(index / 2) | 0] = hash
         indexqueue.push((index / 2) | 0)
       }
       i += 1
@@ -938,6 +1049,40 @@ export class MerkleTree extends Base {
     return !indices.length || (({}).hasOwnProperty.call(tree, 1) && tree[1].equals(root))
   }
 
+  verifyMultiProofWithFlags (
+    root: Buffer | string,
+    leaves: TLeaf[],
+    proofs: Buffer[] | string[],
+    proofFlag: boolean[]
+  ) {
+    root = this.bufferify(root) as Buffer
+    leaves = leaves.map(this.bufferify) as Buffer[]
+    proofs = (proofs as any[]).map(this.bufferify) as Buffer[]
+    const leavesLen = leaves.length
+    const totalHashes = proofFlag.length
+    const hashes : Buffer[] = []
+    let leafPos = 0
+    let hashPos = 0
+    let proofPos = 0
+    for (let i = 0; i < totalHashes; i++) {
+      const bufA: Buffer = proofFlag[i] ? (leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++]) : proofs[proofPos++]
+      const bufB : Buffer = leafPos < leavesLen ? leaves[leafPos++] : hashes[hashPos++]
+      const buffers = [bufA, bufB].sort(Buffer.compare)
+      hashes[i] = this.hashFn(Buffer.concat(buffers))
+    }
+
+    return Buffer.compare(hashes[totalHashes - 1], root) === 0
+  }
+
+  private verifyMultiProofForUnevenTree (root: Buffer | string, indices: number[], leaves: Buffer[] | string[], leavesCount: number, proof: Buffer[] | string[]):boolean {
+    root = this.bufferify(root)
+    leaves = (leaves as any[]).map(leaf => this.bufferify(leaf))
+    proof = (proof as any[]).map(leaf => this.bufferify(leaf))
+
+    const computedRoot = this.calculateRootForUnevenTree(indices, leaves, leavesCount, proof)
+    return root.equals(computedRoot)
+  }
+
   /**
    * getDepth
    * @desc Returns the tree depth (number of layers)
@@ -1087,6 +1232,62 @@ export class MerkleTree extends Base {
   toString ():string {
     return this._toTreeString()
   }
+
+  isUnevenTree (treeLayers?: any[]) {
+    const depth = treeLayers?.length || this.getDepth()
+    return !this.isPowOf2(depth)
+  }
+
+  private isPowOf2 (v: number) {
+    return v && !(v & (v - 1))
+  }
+
+  private calculateRootForUnevenTree (leafIndices: number[], leafHashes: any[], totalLeavesCount: number, proofHashes: any[]) {
+    const leafTuples = this._zip(leafIndices, leafHashes).sort(([indexA], [indexB]) => indexA - indexB)
+    const leafTupleIndices = leafTuples.map(([index]) => index)
+    const proofIndices = this.getProofIndicesForUnevenTree(leafTupleIndices, totalLeavesCount)
+
+    let nextSliceStart = 0
+    const proofTuplesByLayers :any[] = []
+    for (let i = 0; i < proofIndices.length; i++) {
+      const indices = proofIndices[i]
+      const sliceStart = nextSliceStart
+      nextSliceStart += indices.length
+      proofTuplesByLayers[i] = this._zip(indices, proofHashes.slice(sliceStart, nextSliceStart))
+    }
+
+    const tree = [leafTuples]
+    for (let layerIndex = 0; layerIndex < proofTuplesByLayers.length; layerIndex++) {
+      const currentLayer = proofTuplesByLayers[layerIndex].concat(tree[layerIndex]).sort(([indexA], [indexB]) => indexA - indexB)
+        .map(([, hash]) => hash)
+
+      const s = tree[layerIndex].map(([layerIndex]) => layerIndex)
+      const parentIndices = [...new Set(s.map((index: any) => {
+        if (index % 2 === 0) {
+          return index / 2
+        }
+
+        if (index % 2 === 0) {
+          return (index + 1) / 2
+        }
+
+        return (index - 1) / 2
+      }))]
+
+      const parentLayer: any[] = []
+      for (let i = 0; i < parentIndices.length; i++) {
+        const parentNodeTreeIndex = parentIndices[i]
+        const bufA = currentLayer[i * 2]
+        const bufB = currentLayer[i * 2 + 1]
+        const hash = bufB ? this.hashFn(Buffer.concat([bufA, bufB])) : bufA
+        parentLayer.push([parentNodeTreeIndex, hash])
+      }
+
+      tree.push(parentLayer)
+    }
+
+    return tree[tree.length - 1][0][1]
+  }
 }
 
 if (typeof window !== 'undefined') {
diff --git a/test/MerkleTree.test.js b/test/MerkleTree.test.js
index f8fbc1a..98c9cbe 100644
--- a/test/MerkleTree.test.js
+++ b/test/MerkleTree.test.js
@@ -1,7 +1,8 @@
 /* eslint camelcase: 0 */
 
 const test = require('tape')
-const { keccak256 } = require('ethereumjs-util')
+const keccak256 = require('keccak256')
+const { keccak256: ethjskeccak256 } = require('ethereumjs-util')
 const crypto = require('crypto')
 const CryptoJS = require('crypto-js')
 const SHA256 = require('crypto-js/sha256')
@@ -15,7 +16,7 @@ const sha256 = (data) => crypto.createHash('sha256').update(data).digest()
 test('sha256 with keccak256 leaves', t => {
   t.plan(3)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
 
   t.equal(tree.getHexRoot(), '0x311d2e46f49b15fff8b746b74ad57f2cc9e0d9939fda94387141a2d3fdf187ae')
@@ -40,10 +41,18 @@ test('sha256 with keccak256 leaves', t => {
   ])
 })
 
+test('sha256 with ethjs-keccak256 leaves', t => {
+  t.plan(1)
+
+  const leaves = ['a', 'b', 'c'].map(x => ethjskeccak256(Buffer.from(x)))
+  const tree = new MerkleTree(leaves, sha256)
+  t.equal(tree.getHexRoot(), '0x311d2e46f49b15fff8b746b74ad57f2cc9e0d9939fda94387141a2d3fdf187ae')
+})
+
 test('sha256 with keccak256 leaves with duplicate odd option', t => {
   t.plan(3)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256, { duplicateOdd: true })
 
   t.equal(tree.getHexRoot(), '0xbcdd0f60308db788712205115fe4273bfda49fa0925611fee765a63df9ab96a1')
@@ -71,7 +80,7 @@ test('sha256 with keccak256 leaves with duplicate odd option', t => {
 test('crypto-js - sha256', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, SHA256)
   const root = '311d2e46f49b15fff8b746b74ad57f2cc9e0d9939fda94387141a2d3fdf187ae'
 
@@ -81,7 +90,7 @@ test('crypto-js - sha256', t => {
 test('sha256 with sort pairs option', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(x => sha256(x))
+  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(sha256)
   const tree = new MerkleTree(leaves, sha256, { sortPairs: true })
   const root = 'a30ba95a1a5dc397fe45ea20105363b08d682b864a28f4940419a29349a28325'
 
@@ -91,7 +100,7 @@ test('sha256 with sort pairs option', t => {
 test('sha256 - static verify', t => {
   t.plan(2)
 
-  const leaves = ['a', 'b', 'c'].map(x => sha256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(sha256)
   const tree = new MerkleTree(leaves, sha256)
   const leaf = sha256(Buffer.from('a'))
   const badLeaf = sha256(Buffer.from('o'))
@@ -106,7 +115,7 @@ test('sha256 - static verify', t => {
 test('sha256 verify with positional hex proof and no pairSort', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(x => sha256(x))
+  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(sha256)
   const tree = new MerkleTree(leaves, sha256, { sortPairs: false })
 
   t.true(tree.verify(tree.getPositionalHexProof(leaves[1], 1), leaves[1], tree.getHexRoot()))
@@ -115,7 +124,7 @@ test('sha256 verify with positional hex proof and no pairSort', t => {
 test('sha256 verify with non-hex proof and no pairSort', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(x => sha256(x))
+  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(sha256)
   const tree = new MerkleTree(leaves, sha256, { sortPairs: false })
 
   t.true(tree.verify(tree.getProof(leaves[1], 1), leaves[1], tree.getHexRoot()))
@@ -124,7 +133,7 @@ test('sha256 verify with non-hex proof and no pairSort', t => {
 test('sha256 verify with hex proof and pairSort', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(x => sha256(x))
+  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(sha256)
   const tree = new MerkleTree(leaves, sha256, { sortPairs: true })
 
   t.true(tree.verify(tree.getHexProof(leaves[1], 1), leaves[1], tree.getHexRoot()))
@@ -153,7 +162,7 @@ test('keccak256 with sort option', t => {
 test('sha256 with sha256 leaves and sort pairs option and duplicate odd option', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(x => sha256(x))
+  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(sha256)
   const tree = new MerkleTree(leaves, sha256, { sortPairs: true, duplicateOdd: true })
   const root = 'a5260b2a7ec31584e5d5689a5628c2b3d949e2397334fd71c107478e5f887eaf'
 
@@ -193,7 +202,7 @@ test('crypto-js - sha256 with sha256 leaves', t => {
 test('crypto-js - sha256 with keccak256 leaves and duplicate odd option', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, SHA256, { duplicateOdd: true })
   const root = 'bcdd0f60308db788712205115fe4273bfda49fa0925611fee765a63df9ab96a1'
 
@@ -224,7 +233,7 @@ test('crypto-js - SHA256 with SHA3 leaves', t => {
 test('crypto-js - SHA256 with keccak256 leaves and duplicate odd option', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, SHA256, { duplicateOdd: true })
   const root = 'bcdd0f60308db788712205115fe4273bfda49fa0925611fee765a63df9ab96a1'
 
@@ -234,7 +243,7 @@ test('crypto-js - SHA256 with keccak256 leaves and duplicate odd option', t => {
 test('solidity keccak256', t => {
   t.plan(20)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
 
   const a_hash = '3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1cb'
   const b_hash = 'b5553de315e0edf504d9150af82dafa5c4667fa618ed0a6f19c69b41166c5510'
@@ -283,7 +292,7 @@ test('solidity keccak256', t => {
 test('solidity keccak256 with duplicate odd option', t => {
   t.plan(20)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
 
   const a_hash = '3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1cb'
   const b_hash = 'b5553de315e0edf504d9150af82dafa5c4667fa618ed0a6f19c69b41166c5510'
@@ -330,7 +339,7 @@ test('solidity keccak256 with duplicate odd option', t => {
 test('solidity keccak256 with duplicate leaves', t => {
   t.plan(5)
 
-  const leaves = ['a', 'b', 'a'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'a'].map(keccak256)
 
   const a_hash = '3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1cb'
   const b_hash = 'b5553de315e0edf504d9150af82dafa5c4667fa618ed0a6f19c69b41166c5510'
@@ -472,7 +481,7 @@ test('sha-256 with option.isBitcoinTree', t => {
 
 test('keccak256 - hex strings', t => {
   t.plan(1)
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)).toString('hex'))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, SHA256)
   const root = '311d2e46f49b15fff8b746b74ad57f2cc9e0d9939fda94387141a2d3fdf187ae'
   t.equal(tree.getRoot().toString('hex'), root)
@@ -496,7 +505,7 @@ test.skip('sha256 - 1,000,000 leaves', t => {
     values.push(`${i}`)
   }
 
-  const leaves = values.map(x => sha256(x))
+  const leaves = values.map(sha256)
   const tree = new MerkleTree(leaves, sha256)
   const root = '101dd357df60384d254330fe118e3046871767c2748ebd62ce031c117df483da'
 
@@ -506,7 +515,7 @@ test.skip('sha256 - 1,000,000 leaves', t => {
 test('sha256 getHexLeaves', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
   t.deepEqual(tree.getHexLeaves(), [
     '0x3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1cb',
@@ -598,7 +607,7 @@ test('sha1', t => {
 test('sha56 getHexLayers', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
   const layers = tree.getHexLayers()
 
@@ -621,7 +630,7 @@ test('sha56 getHexLayers', t => {
 test('getLayersAsObject', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
   const obj = tree.getLayersAsObject()
 
@@ -641,7 +650,7 @@ test('getLayersAsObject', t => {
 test('getLayersAsObject with duplicate odd option', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256, { duplicateOdd: true })
   const obj = tree.getLayersAsObject()
 
@@ -658,26 +667,27 @@ test('getLayersAsObject with duplicate odd option', t => {
   })
 })
 
-test.skip('sha256 getHexLayersFlat', t => {
+test('sha256 getHexLayersFlat', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
-  const layers = tree.getLayersFlat()
+  const layers = tree.getHexLayersFlat()
   t.deepEqual(layers, [
-    '3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1cb',
-    'b5553de315e0edf504d9150af82dafa5c4667fa618ed0a6f19c69b41166c5510',
-    '0b42b6393c1f53060fe3ddbfcd7aadcca894465a5a438f69c87d790b2299b9b2',
-    '176f0f307632fdd5831875eb709e2f68d770b102262998b214ddeb3f04164ae1',
-    '0b42b6393c1f53060fe3ddbfcd7aadcca894465a5a438f69c87d790b2299b9b2',
-    '311d2e46f49b15fff8b746b74ad57f2cc9e0d9939fda94387141a2d3fdf187ae'
+    '0x00',
+    '0x311d2e46f49b15fff8b746b74ad57f2cc9e0d9939fda94387141a2d3fdf187ae',
+    '0x176f0f307632fdd5831875eb709e2f68d770b102262998b214ddeb3f04164ae1',
+    '0x0b42b6393c1f53060fe3ddbfcd7aadcca894465a5a438f69c87d790b2299b9b2',
+    '0x3ac225168df54212a25c1c01fd35bebfea408fdac2e31ddd6f80a4bbf9a5f1cb',
+    '0xb5553de315e0edf504d9150af82dafa5c4667fa618ed0a6f19c69b41166c5510',
+    '0x0b42b6393c1f53060fe3ddbfcd7aadcca894465a5a438f69c87d790b2299b9b2'
   ])
 })
 
 test('print', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
 
   t.equal(tree.toString(),
@@ -693,7 +703,7 @@ test('print', t => {
 test('print with duplicate odd option', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256, { duplicateOdd: true })
 
   t.equal(tree.toString(),
@@ -706,7 +716,7 @@ test('print with duplicate odd option', t => {
 `)
 })
 
-test('sha256 getMultiProof', t => {
+test('sha256 getMultiProof + verifyMultiProof', t => {
   t.plan(3)
 
   const leaves = Array(16).fill(0).map((x, i) => {
@@ -720,10 +730,10 @@ test('sha256 getMultiProof', t => {
   const root = tree.getHexRoot()
   t.equal(root, '0xc1ebc5b83154907160d73863bdae7eb86fe1888495a83cb8daadb1603b8aeaf5')
 
-  const i = 100
-  const indices = Array(16).fill(0).map((x, j) => j).filter(j => (i >> j) % 2 === 1)
+  const n = 100
+  const proofIndices = Array(16).fill(0).map((x, j) => j).filter(j => (n >> j) % 2 === 1)
 
-  const proof = tree.getMultiProof(indices)
+  const proof = tree.getMultiProof(proofIndices)
 
   t.deepEqual(proof.map(x => x.toString('hex')), [
     '0000000000000000000000000000000000000000000000000000000000000007',
@@ -735,8 +745,49 @@ test('sha256 getMultiProof', t => {
 
   const depth = tree.getDepth()
 
-  const tLeaves = indices.map(i => leaves[i])
-  t.true(tree.verifyMultiProof(root, indices, tLeaves, depth, proof))
+  const proofLeaves = proofIndices.map(i => leaves[i])
+  t.true(tree.verifyMultiProof(root, proofIndices, proofLeaves, depth, proof))
+})
+
+test('keccak256 verifyMultiProofWithFlags', t => {
+  t.plan(4)
+
+  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(keccak256).sort(Buffer.compare)
+
+  const tree = new MerkleTree(leaves, keccak256, { sort: true })
+  const root = tree.getHexRoot()
+  t.equal(root, '0x1b404f199ea828ec5771fb30139c222d8417a82175fefad5cd42bc3a189bd8d5')
+
+  const proofLeaves = [keccak256('b'), keccak256('d'), keccak256('f')].sort(Buffer.compare)
+  t.deepEqual(proofLeaves.map(x => x.toString('hex')), ['b5553de315e0edf504d9150af82dafa5c4667fa618ed0a6f19c69b41166c5510',
+    'd1e8aeb79500496ef3dc2e57ba746a8315d048b7a664a2bf948db4fa91960483',
+    'f1918e8562236eb17adc8502332f4c9c82bc14e19bfc0aa10ab674ff75b3d2f3'
+  ])
+
+  const proof = tree.getMultiProof(proofLeaves)
+  t.deepEqual(proof.map(x => x.toString('hex')), [
+    'a8982c89d80987fb9a510e25981ee9170206be21af3c8e0eb312ef1d3382e761',
+    '7dea550f679f3caab547cbbc5ee1a4c978c8c039b572ba00af1baa6481b88360'
+  ])
+  const proofFlags = tree.getProofFlags(proofLeaves, proof)
+  t.true(tree.verifyMultiProofWithFlags(root, proofLeaves, proof, proofFlags))
+})
+
+test('keccak256 getMultiProof uneven tree', t => {
+  t.plan(3)
+
+  const leaves = ['a', 'b', 'c', 'd', 'e', 'f'].map(sha256)
+  const tree = new MerkleTree(leaves, sha256)
+  const root = tree.getRoot()
+  t.equal(root.toString('hex'), '1f7379539707bcaea00564168d1d4d626b09b73f8a2a365234c62d763f854da2')
+  const indicesToProve = [3, 4]
+  const leavesToProve = indicesToProve.map((index) => leaves[index])
+  const proof = tree.getMultiProof(indicesToProve)
+  t.deepEqual(proof.map(x => x.toString('hex')), ['2e7d2c03a9507ae265ecf5b5356885a53393a2029d241394997265a1a25aefc6',
+    '252f10c83610ebca1a059c0bae8255eba2f95be4d1d7bcfa89d7248a82d9f111',
+    'e5a01fee14e0ed5c48714f22180f25ad8365b53f9779f79dc4a3d7e93963f94a'
+  ])
+  t.true(tree.verifyMultiProof(root, indicesToProve, leavesToProve, leaves.length, proof))
 })
 
 test('sha256 getMultiProof with pairs sorted', t => {
@@ -751,14 +802,14 @@ test('sha256 getMultiProof with pairs sorted', t => {
   const tree = new MerkleTree(leaves, sha256, { sortPairs: true })
   const root = tree.getHexRoot()
 
-  const i = 100
-  const indices = Array(16).fill(0).map((x, j) => j).filter(j => (i >> j) % 2 === 1)
+  const n = 100
+  const proofIndices = Array(16).fill(0).map((x, j) => j).filter(j => (n >> j) % 2 === 1)
 
-  const proof = tree.getMultiProof(indices)
+  const proof = tree.getMultiProof(proofIndices)
   const depth = tree.getDepth()
-  const tLeaves = indices.map(i => leaves[i])
+  const proofLeaves = proofIndices.map(i => leaves[i])
 
-  t.true(tree.verifyMultiProof(root, indices, tLeaves, depth, proof))
+  t.true(tree.verifyMultiProof(root, proofIndices, proofLeaves, depth, proof))
 })
 
 test('sha256 getMultiProof using tree array', t => {
@@ -812,8 +863,8 @@ test('sha256 getMultiProof using tree array', t => {
     '000000000000000000000000000000000000000000000000000000000000000f'
   ])
 
-  const indices = [2, 5, 6]
-  const proof = tree.getMultiProof(treeFlat, indices)
+  const proofIndices = [2, 5, 6]
+  const proof = tree.getMultiProof(treeFlat, proofIndices)
 
   t.deepEqual(proof.map(x => x.toString('hex')), [
     '0000000000000000000000000000000000000000000000000000000000000007',
@@ -826,9 +877,9 @@ test('sha256 getMultiProof using tree array', t => {
   const depth = tree.getDepth()
   t.equal(depth, Math.log2((treeFlat.length / 2) | 0))
 
-  const tRoot = treeFlat[1]
-  const tLeaves = indices.map(i => leaves[i])
-  t.true(tree.verifyMultiProof(tRoot, indices, tLeaves, depth, proof))
+  const treeRoot = treeFlat[1]
+  const proofLeaves = proofIndices.map(i => leaves[i])
+  t.true(tree.verifyMultiProof(treeRoot, proofIndices, proofLeaves, depth, proof))
 })
 
 test('sha256 getMultiProof', t => {
@@ -847,9 +898,9 @@ test('sha256 getMultiProof', t => {
 
   const treeFlat = tree.getLayersFlat()
 
-  const indices = [0, 1]
-  const proof = tree.getMultiProof(treeFlat, indices)
-  const tLeaves = indices.map(i => leaves[i])
+  const proofIndices = [0, 1]
+  const proof = tree.getMultiProof(treeFlat, proofIndices)
+  const proofLeaves = proofIndices.map(i => leaves[i])
 
   t.deepEqual(proof.map(x => x.toString('hex')), [
     'a774c351cf3882b36b2c541586b0b59c6dfd119ae831ef3c6b2e269f7a6be220',
@@ -857,7 +908,7 @@ test('sha256 getMultiProof', t => {
     '44f76d663f391971ba8bd22469061c70aa63c176bc29b651336db7587b6f5a6c'
   ])
 
-  const proofFlags = tree.getProofFlags(tLeaves, proof)
+  const proofFlags = tree.getProofFlags(proofLeaves, proof)
   t.deepEqual(proofFlags, [
     true,
     false,
@@ -875,10 +926,10 @@ test('sha256 getProofFlag with indices', t => {
   t.equal(root, '0x4c6aae040ffada3d02598207b8485fcbe161c03f4cb3f660e4d341e7496ff3b2')
 
   const treeFlat = tree.getLayersFlat()
-  const indices = [1, 2]
-  const proof = tree.getMultiProof(treeFlat, indices)
+  const proofIndices = [1, 2]
+  const proof = tree.getMultiProof(treeFlat, proofIndices)
 
-  const proofFlags = tree.getProofFlags(indices, proof)
+  const proofFlags = tree.getProofFlags(proofIndices, proof)
   t.deepEqual(proofFlags, [
     false,
     false,
@@ -926,7 +977,7 @@ test('sha256 getMultiProof - statusim', t => {
 test('marshal leaves', t => {
   t.plan(5)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const jsonLeaves = MerkleTree.marshalLeaves(leaves)
   t.equal(typeof jsonLeaves, 'string')
 
@@ -956,7 +1007,7 @@ test('unmarshal leaves', t => {
 test('marshal proof', t => {
   t.plan(5)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256, { duplicateOdd: true })
   const proof = tree.getProof(leaves[0])
 
@@ -1011,7 +1062,7 @@ test('fillDefaultHashes', t => {
 test('getLeafIndex', t => {
   t.plan(5)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
 
   t.equal(tree.getHexRoot(), '0x311d2e46f49b15fff8b746b74ad57f2cc9e0d9939fda94387141a2d3fdf187ae')
@@ -1024,7 +1075,7 @@ test('getLeafIndex', t => {
 test('getleafCount', t => {
   t.plan(1)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
 
   t.equal(tree.getLeafCount(), 3)
@@ -1033,7 +1084,7 @@ test('getleafCount', t => {
 test('getleaf', t => {
   t.plan(5)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
 
   t.deepEqual(tree.getLeaf(-1), Buffer.from([]))
@@ -1046,7 +1097,7 @@ test('getleaf', t => {
 test('addLeaf', t => {
   t.plan(2)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree([], sha256)
   tree.addLeaf(leaves[0])
   tree.addLeaf(leaves[1])
@@ -1063,7 +1114,7 @@ test('addLeaf', t => {
 test('addLeaves', t => {
   t.plan(3)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree([], sha256)
   tree.addLeaves(leaves)
 
@@ -1074,7 +1125,7 @@ test('addLeaves', t => {
     '0x0b42b6393c1f53060fe3ddbfcd7aadcca894465a5a438f69c87d790b2299b9b2'
   ])
 
-  const moreLeaves = ['d', 'e', 'f'].map(x => keccak256(Buffer.from(x)))
+  const moreLeaves = ['d', 'e', 'f'].map(keccak256)
   tree.addLeaves(moreLeaves)
   t.equal(tree.getHexRoot(), '0xb9a721d82428976e0d500f97646bf273ec1dd9c2104b9328873a94fc3897aec6')
 })
@@ -1082,7 +1133,7 @@ test('addLeaves', t => {
 test('resetTree', t => {
   t.plan(2)
 
-  const leaves = ['a', 'b', 'c'].map(x => keccak256(Buffer.from(x)))
+  const leaves = ['a', 'b', 'c'].map(keccak256)
   const tree = new MerkleTree(leaves, sha256)
 
   t.equal(tree.getLeafCount(), 3)