diff --git a/src/bigbuffer.js b/src/bigbuffer.js
index 1064a02..e2247e3 100644
--- a/src/bigbuffer.js
+++ b/src/bigbuffer.js
@@ -1,5 +1,5 @@
 
-const PAGE_SIZE = 1<<30;
+const PAGE_SIZE = ( typeof Buffer !== "undefined" && Buffer.constants && Buffer.constants.MAX_LENGTH ) ? Buffer.constants.MAX_LENGTH : (1 << 30);
 
 export default class BigBuffer {
 
@@ -8,7 +8,8 @@ export default class BigBuffer {
         this.byteLength = size;
         for (let i=0; i<size; i+= PAGE_SIZE) {
             const n = Math.min(size-i, PAGE_SIZE);
-            this.buffers.push(new Uint8Array(n));
+            //this.buffers.push(new Uint8Array(n));
+            this.buffers.push(new Uint8Array(new SharedArrayBuffer(n)));
         }
 
     }
diff --git a/src/engine_applykey.js b/src/engine_applykey.js
index 5857d8c..294c9ff 100644
--- a/src/engine_applykey.js
+++ b/src/engine_applykey.js
@@ -64,10 +64,12 @@ export default function buildBatchApplyKey(curve, groupName) {
 
             const task = [];
 
+            const b = buff.slice(i*pointsPerChunk*sGin, i*pointsPerChunk*sGin + n*sGin);
+
             task.push({
                 cmd: "ALLOCSET",
                 var: 0,
-                buff: buff.slice(i*pointsPerChunk*sGin, i*pointsPerChunk*sGin + n*sGin)
+                buff: b
             });
             task.push({cmd: "ALLOCSET", var: 1, buff: t});
             task.push({cmd: "ALLOCSET", var: 2, buff: inc});
@@ -96,7 +98,7 @@ export default function buildBatchApplyKey(curve, groupName) {
             }
             task.push({cmd: "GET", out: 0, var: 3, len: n*sGout});
 
-            opPromises.push(tm.queueAction(task));
+            opPromises.push(tm.queueAction(task, [b.buffer]));
             t = Fr.mul(t, Fr.exp(inc, n));
         }
 
diff --git a/src/engine_batchconvert.js b/src/engine_batchconvert.js
index 0acf524..1adb3bf 100644
--- a/src/engine_batchconvert.js
+++ b/src/engine_batchconvert.js
@@ -29,7 +29,7 @@ export default function buildBatchConvert(tm, fnName, sIn, sOut) {
                 {cmd: "GET", out: 0, var: 1, len:sOut * n},
             ];
             opPromises.push(
-                tm.queueAction(task)
+                tm.queueAction(task, [buffChunk.buffer])
             );
         }
 
diff --git a/src/engine_fft.js b/src/engine_fft.js
index 5ae955b..2dae88d 100644
--- a/src/engine_fft.js
+++ b/src/engine_fft.js
@@ -146,7 +146,7 @@ export default function buildFFT(curve, groupName) {
             } else {
                 task.push({cmd: "GET", out:0, var: 0, len: sMid*pointsInChunk});
             }
-            promises.push(tm.queueAction(task).then( (r) => {
+            promises.push(tm.queueAction(task, [buffChunk.buffer]).then( (r) => {
                 if (logger) logger.debug(`${loggerTxt}: fft ${bits} mix end: ${i}/${nChunks}`);
                 return r;
             }));
@@ -203,7 +203,7 @@ export default function buildFFT(curve, groupName) {
                         task.push({cmd: "GET", out: 0, var: 0, len: pointsInChunk*sMid});
                         task.push({cmd: "GET", out: 1, var: 1, len: pointsInChunk*sMid});
                     }
-                    opPromises.push(tm.queueAction(task).then( (r) => {
+                    opPromises.push(tm.queueAction(task, [chunks[o1].buffer, chunks[o2].buffer, first.buffer ]).then( (r) => {
                         if (logger) logger.debug(`${loggerTxt}: fft ${bits} join  ${i}/${bits}  ${j+1}/${nGroups} ${k}/${nChunksPerGroup/2}`);
                         return r;
                     }));
@@ -402,7 +402,7 @@ export default function buildFFT(curve, groupName) {
             task.push({cmd: "GET", out: 0, var: 0, len: n*sOut});
             task.push({cmd: "GET", out: 1, var: 1, len: n*sOut});
             opPromises.push(
-                tm.queueAction(task).then( (r) => {
+                tm.queueAction(task, [b1.buffer, b2.buffer, firstChunk.buffer]).then((r) => {
                     if (logger) logger.debug(`${loggerTxt}: fftJoinExt End: ${i}/${nPoints}`);
                     return r;
                 })
@@ -550,7 +550,7 @@ export default function buildFFT(curve, groupName) {
             }
             task.push({cmd: "GET", out: 0, var: 0, len: pointsPerChunk*sG});
             opPromises.push(
-                tm.queueAction(task)
+                tm.queueAction(task, [b.buffer])
             );
         }
 
@@ -585,7 +585,7 @@ export default function buildFFT(curve, groupName) {
                     ]});
                     task.push({cmd: "GET", out: 0, var: 0, len: pointsPerChunk*sG});
                     task.push({cmd: "GET", out: 1, var: 1, len: pointsPerChunk*sG});
-                    opPromises.push(tm.queueAction(task));
+                    opPromises.push(tm.queueAction(task, [chunks[o1].buffer, chunks[o2].buffer, first.buffer]));
                 }
             }
 
@@ -664,7 +664,7 @@ export default function buildFFT(curve, groupName) {
             task.push({cmd: "GET", out: 0, var: 0, len: pointsPerChunk*sG});
             task.push({cmd: "GET", out: 1, var: 1, len: pointsPerChunk*sG});
             opPromises.push(
-                tm.queueAction(task)
+                tm.queueAction(task, [b1.buffer, b2.buffer, firstChunk.buffer])
             );
 
         }
@@ -740,7 +740,7 @@ export default function buildFFT(curve, groupName) {
             ]});
             task.push({cmd: "GET", out: 0, var: 0, len: n*sGout});
             opPromises.push(
-                tm.queueAction(task)
+                tm.queueAction(task, [b.buffer])
             );
 
         }
diff --git a/src/engine_multiexp.js b/src/engine_multiexp.js
index 38d813f..498e3cd 100644
--- a/src/engine_multiexp.js
+++ b/src/engine_multiexp.js
@@ -10,6 +10,7 @@ const pTSizes = [
 export default function buildMultiexp(curve, groupName) {
     const G = curve[groupName];
     const tm = G.tm;
+
     async function _multiExpChunk(buffBases, buffScalars, inType, logger, logText) {
         if ( ! (buffBases instanceof Uint8Array) ) {
             if (logger) logger.error(`${logText} _multiExpChunk buffBases is not Uint8Array`);
@@ -23,20 +24,20 @@ export default function buildMultiexp(curve, groupName) {
 
         let sGIn;
         let fnName;
-        if (groupName == "G1") {
-            if (inType == "affine") {
-                fnName = "g1m_multiexpAffine_chunk";
+        if (groupName === "G1") {
+            if (inType === "affine") {
+                fnName = "g1m_multiexpAffine";
                 sGIn = G.F.n8*2;
             } else {
-                fnName = "g1m_multiexp_chunk";
+                fnName = "g1m_multiexp";
                 sGIn = G.F.n8*3;
             }
-        } else if (groupName == "G2") {
-            if (inType == "affine") {
-                fnName = "g2m_multiexpAffine_chunk";
+        } else if (groupName === "G2") {
+            if (inType === "affine") {
+                fnName = "g2m_multiexpAffine";
                 sGIn = G.F.n8*2;
             } else {
-                fnName = "g2m_multiexp_chunk";
+                fnName = "g2m_multiexp";
                 sGIn = G.F.n8*3;
             }
         } else {
@@ -44,36 +45,33 @@ export default function buildMultiexp(curve, groupName) {
         }
         const nPoints = Math.floor(buffBases.byteLength / sGIn);
 
-        if (nPoints == 0) return G.zero;
+        if (nPoints === 0) return G.zero;
         const sScalar = Math.floor(buffScalars.byteLength / nPoints);
-        if( sScalar * nPoints != buffScalars.byteLength) {
+        if( sScalar * nPoints !== buffScalars.byteLength) {
             throw new Error("Scalar size does not match");
         }
 
         const bitChunkSize = pTSizes[log2(nPoints)];
-        const nChunks = Math.floor((sScalar*8 - 1) / bitChunkSize) +1;
 
         const opPromises = [];
-        for (let i=0; i<nChunks; i++) {
-            const task = [
-                {cmd: "ALLOCSET", var: 0, buff: buffBases},
-                {cmd: "ALLOCSET", var: 1, buff: buffScalars},
-                {cmd: "ALLOC", var: 2, len: G.F.n8*3},
-                {cmd: "CALL", fnName: fnName, params: [
-                    {var: 0},
-                    {var: 1},
-                    {val: sScalar},
-                    {val: nPoints},
-                    {val: i*bitChunkSize},
-                    {val: Math.min(sScalar*8 - i*bitChunkSize, bitChunkSize)},
-                    {var: 2}
-                ]},
-                {cmd: "GET", out: 0, var: 2, len: G.F.n8*3}
-            ];
-            opPromises.push(
-                G.tm.queueAction(task)
-            );
-        }
+
+        const task = [
+            {cmd: "ALLOCSET", var: 0, buff: buffBases},
+            {cmd: "ALLOCSET", var: 1, buff: buffScalars},
+            {cmd: "ALLOC", var: 2, len: G.F.n8*3},
+            {cmd: "CALL", fnName: fnName, params: [
+                {var: 0}, //pBases
+                {var: 1}, // pScalars
+                {val: sScalar}, // scalarSize
+                {val: nPoints}, // nPoints
+                {var: 2} // pr
+            ]},
+            {cmd: "GET", out: 0, var: 2, len: G.F.n8*3}
+        ];
+        opPromises.push(
+            // transfer ownership of the buffers to the worker thread
+            G.tm.queueAction(task, [buffBases.buffer, buffScalars.buffer])
+        );
 
         const result = await Promise.all(opPromises);
 
@@ -93,14 +91,14 @@ export default function buildMultiexp(curve, groupName) {
         const MIN_CHUNK_SIZE = 1 << 10;
         let sGIn;
 
-        if (groupName == "G1") {
-            if (inType == "affine") {
+        if (groupName === "G1") {
+            if (inType === "affine") {
                 sGIn = G.F.n8*2;
             } else {
                 sGIn = G.F.n8*3;
             }
-        } else if (groupName == "G2") {
-            if (inType == "affine") {
+        } else if (groupName === "G2") {
+            if (inType === "affine") {
                 sGIn = G.F.n8*2;
             } else {
                 sGIn = G.F.n8*3;
@@ -110,33 +108,49 @@ export default function buildMultiexp(curve, groupName) {
         }
 
         const nPoints = Math.floor(buffBases.byteLength / sGIn);
-        if (nPoints == 0) return G.zero;
+        if (nPoints === 0) return G.zero;
         const sScalar = Math.floor(buffScalars.byteLength / nPoints);
-        if( sScalar * nPoints != buffScalars.byteLength) {
+        if( sScalar * nPoints !== buffScalars.byteLength) {
             throw new Error("Scalar size does not match");
         }
 
+        console.log("buffBases.buffer instanceof SharedArrayBuffer", buffBases.buffer instanceof SharedArrayBuffer);
+        console.log("buffScalars.buffer instanceof SharedArrayBuffer", buffScalars.buffer instanceof SharedArrayBuffer);
+
+        let result = [];
+        const opPromises = [];
         const bitChunkSize = pTSizes[log2(nPoints)];
-        const nChunks = Math.floor((sScalar*8 - 1) / bitChunkSize) +1;
+        let nChunks = Math.floor((sScalar*8 - 1) / bitChunkSize) +1;
+
+        if (groupName === "G2") {
+            // G2 has bigger points, so we reduce chunk size to optimize memory usage
+            nChunks *= 2;
+        }
 
         let chunkSize;
-        chunkSize = Math.floor(nPoints / (tm.concurrency /nChunks));
+        //chunkSize = Math.floor(nPoints / tm.concurrency) + 1;
+
+        // make nChunks multiple of tm.concurrency for optimal load balancing
+        nChunks = (Math.floor((nChunks-1) / tm.concurrency) + 1) * tm.concurrency;
+        chunkSize = Math.floor(nPoints / nChunks) + 1;
+
         if (chunkSize>MAX_CHUNK_SIZE) chunkSize = MAX_CHUNK_SIZE;
         if (chunkSize<MIN_CHUNK_SIZE) chunkSize = MIN_CHUNK_SIZE;
 
-        const opPromises = [];
         for (let i=0; i<nPoints; i += chunkSize) {
             if (logger) logger.debug(`Multiexp start: ${logText}: ${i}/${nPoints}`);
-            const n= Math.min(nPoints - i, chunkSize);
+            const n = Math.min(nPoints - i, chunkSize);
+
             const buffBasesChunk = buffBases.slice(i*sGIn, (i+n)*sGIn);
             const buffScalarsChunk = buffScalars.slice(i*sScalar, (i+n)*sScalar);
-            opPromises.push(_multiExpChunk(buffBasesChunk, buffScalarsChunk, inType, logger, logText).then( (r) => {
+
+            opPromises.push(_multiExpChunk(buffBasesChunk, buffScalarsChunk, inType, logger, logText).then((r) => {
                 if (logger) logger.debug(`Multiexp end: ${logText}: ${i}/${nPoints}`);
                 return r;
             }));
         }
 
-        const result = await Promise.all(opPromises);
+        result = await Promise.all(opPromises);
 
         let res = G.zero;
         for (let i=result.length-1; i>=0; i--) {
diff --git a/src/engine_pairing.js b/src/engine_pairing.js
index 5a802ce..39095d2 100644
--- a/src/engine_pairing.js
+++ b/src/engine_pairing.js
@@ -60,7 +60,7 @@ export default function buildPairing(curve) {
             task.push({cmd: "GET", out: 0, var: 4, len: curve.Gt.n8});
 
             opPromises.push(
-                tm.queueAction(task)
+                tm.queueAction(task, [g1Buff.buffer, g2Buff.buffer])
             );
         }
 
diff --git a/src/threadman.js b/src/threadman.js
index f80901b..38f46fc 100644
--- a/src/threadman.js
+++ b/src/threadman.js
@@ -110,7 +110,7 @@ export default async function buildThreadManager(wasm, singleThread) {
             concurrency = os.cpus().length;
         }
 
-        if(concurrency == 0){
+        if(concurrency === 0){
             concurrency = 2;
         }
 
@@ -151,6 +151,13 @@ export default async function buildThreadManager(wasm, singleThread) {
                 data = e;
             }
 
+            // handle errors
+            if (data.error) {
+                tm.working[i]=false;
+                tm.pendingDeferreds[i].reject("Worker error: " + data.error);
+                throw new Error("Worker error: " + data.error);
+            }
+
             tm.working[i]=false;
             tm.pendingDeferreds[i].resolve(data);
             tm.processWorks();
@@ -166,19 +173,19 @@ export class ThreadManager {
     }
 
     startSyncOp() {
-        if (this.oldPFree != 0) throw new Error("Sync operation in progress");
+        if (this.oldPFree !== 0) throw new Error("Sync operation in progress");
         this.oldPFree = this.u32[0];
     }
 
     endSyncOp() {
-        if (this.oldPFree == 0) throw new Error("No sync operation in progress");
+        if (this.oldPFree === 0) throw new Error("No sync operation in progress");
         this.u32[0] = this.oldPFree;
         this.oldPFree = 0;
     }
 
     postAction(workerId, e, transfers, _deferred) {
         if (this.working[workerId]) {
-            throw new Error("Posting a job t a working worker");
+            throw new Error("Posting a job to a working worker");
         }
         this.working[workerId] = true;
 
@@ -189,8 +196,11 @@ export class ThreadManager {
     }
 
     processWorks() {
+        if (this.workers.length === 0 && this.actionQueue.length > 0) {
+            throw new Error("No workers initialized");
+        }
         for (let i=0; (i<this.workers.length)&&(this.actionQueue.length > 0); i++) {
-            if (this.working[i] == false) {
+            if (this.working[i] === false) {
                 const work = this.actionQueue.shift();
                 this.postAction(i, work.data, work.transfers, work.deferred);
             }
diff --git a/src/threadman_thread.js b/src/threadman_thread.js
index 09951ba..726dbe9 100644
--- a/src/threadman_thread.js
+++ b/src/threadman_thread.js
@@ -14,15 +14,20 @@ export default function thread(self) {
                 data = e;
             }
 
-            if (data[0].cmd == "INIT") {
-                init(data[0]).then(function() {
-                    self.postMessage(data.result);
-                });
-            } else if (data[0].cmd == "TERMINATE") {
-                self.close();
-            } else {
-                const res = runTask(data);
-                self.postMessage(res);
+            try {
+                if (data[0].cmd === "INIT") {
+                    init(data[0]).then(function() {
+                        self.postMessage(data.result);
+                    });
+                } else if (data[0].cmd === "TERMINATE") {
+                    self.close();
+                } else {
+                    const res = runTask(data);
+                    self.postMessage(res);
+                }
+            } catch (err) {
+                // Catch any error and send it back to main thread
+                self.postMessage({error: err.message});
             }
         };
     }
@@ -72,7 +77,7 @@ export default function thread(self) {
     }
 
     function runTask(task) {
-        if (task[0].cmd == "INIT") {
+        if (task[0].cmd === "INIT") {
             return init(task[0]);
         }
         const ctx = {
diff --git a/src/wasm_field1.js b/src/wasm_field1.js
index e5c3b64..7dbd8bb 100644
--- a/src/wasm_field1.js
+++ b/src/wasm_field1.js
@@ -282,7 +282,7 @@ export default class WasmField1 {
                 {cmd: "GET", out: 0, var: 1, len:sOut * n},
             ];
             opPromises.push(
-                this.tm.queueAction(task)
+                this.tm.queueAction(task, [buffChunk.buffer])
             );
         }