diff --git a/codex/erasure/asyncbackend.nim b/codex/erasure/asyncbackend.nim
index f3bca851..8bcf9436 100644
--- a/codex/erasure/asyncbackend.nim
+++ b/codex/erasure/asyncbackend.nim
@@ -8,6 +8,7 @@
 ## those terms.
 
 import std/sequtils
+import std/sugar
 
 import pkg/taskpools
 import pkg/taskpools/flowvars
@@ -15,6 +16,9 @@ import pkg/chronos
 import pkg/chronos/threadsync
 import pkg/questionable/results
 
+import pkg/libp2p/[cid, multicodec, multihash]
+import pkg/stew/io2
+
 import ./backend
 import ../errors
 import ../logutils
@@ -50,6 +54,49 @@ type
   EncodeTaskResult = Result[SharedArrayHolder[byte], cstring]
   DecodeTaskResult = Result[SharedArrayHolder[byte], cstring]
 
+proc dumpOf(prefix: string, bytes: seq[seq[byte]]): void = 
+  for i in 0..<bytes.len:
+    if bytes[i].len > 0:
+      io2.writeFile(prefix & $i, bytes[i]).tryGet()
+
+proc hashOf(bytes: ref seq[seq[byte]]): string =
+  var totalLen = 0
+  for i in 0..<len(bytes[]):
+    totalLen = totalLen + bytes[i].len
+
+  var buf = newSeq[byte]()
+
+  buf.setLen(totalLen)
+
+  var offset = 0
+  for i in 0..<len(bytes[]):
+    if bytes[i].len > 0:
+      copyMem(addr buf[offset], addr bytes[i][0], bytes[i].len)
+      offset = offset + bytes[i].len
+
+  let mhash = MultiHash.digest("sha2-256", buf)
+  return mhash.get().hex
+
+proc unsafeHashOf(bytes: seq[pointer], lens: seq[int]): string =
+  var totalLen = 0
+  for l in lens:
+    totalLen = totalLen + l
+
+  var buf = newSeq[byte]()
+
+  buf.setLen(totalLen)
+
+  var offset = 0
+  for i in 0..<lens.len:
+    echo "pointer " & $i & " " & bytes[i].repr
+    let l = lens[i]
+    if l > 0:
+      copyMem(addr buf[offset], bytes[i], l)
+      offset = offset + l
+
+  let mhash = MultiHash.digest("sha2-256", buf)
+  return mhash.get().hex
+
 proc encodeTask(args: EncodeTaskArgs, data: seq[seq[byte]]): EncodeTaskResult =
   var
     data = data.unsafeAddr
@@ -79,12 +126,42 @@ proc encodeTask(args: EncodeTaskArgs, data: seq[seq[byte]]): EncodeTaskResult =
     if err =? args.signal.fireSync().mapFailure.errorOption():
       error "Error firing signal", msg = err.msg
 
-proc decodeTask(args: DecodeTaskArgs, data: seq[seq[byte]], parity: seq[seq[byte]]): DecodeTaskResult =
+proc decodeTask(args: DecodeTaskArgs, odata: seq[seq[byte]], oparity: seq[seq[byte]], debug: bool): DecodeTaskResult =
+
+  if debug:
+    dumpOf("thread_data_", odata)
+    dumpOf("thread_parity", oparity)
+  # if debugFlag:
+    # io2.writeFile("original_block_" & $idx, blk.data).tryGet()
+
+  var ptrsData: seq[pointer]
+  for i in 0..<odata.len:
+    if odata[i].len > 0:
+      ptrsData.add(unsafeAddr odata[i][0])
+    else:
+      ptrsData.add(unsafeAddr odata)
+
+  var ptrsParity: seq[pointer]
+  for i in 0..<oparity.len:
+    if oparity[i].len > 0:
+      ptrsParity.add(unsafeAddr oparity[i][0])
+    else:
+      ptrsParity.add(unsafeAddr oparity)
+
+  echo "bef unsafe hash of data " & unsafeHashOf(ptrsData, odata.mapIt(it.len))
+  echo "bef unsafe hash of parity " & unsafeHashOf(ptrsParity, oparity.mapIt(it.len))
+
+  var
+    data = odata.unsafeAddr
+    parity = oparity.unsafeAddr
+
   var
-    data = data.unsafeAddr
-    parity = parity.unsafeAddr
     recovered = newSeqWith[seq[byte]](args.ecK, newSeq[byte](args.blockSize))
 
+  var ptrs: seq[pointer]
+  for i in 0..<recovered.len:
+    ptrs.add(unsafeAddr recovered[i][0])
+
   try:
     let res = args.backend[].decode(data[], parity[], recovered)
 
@@ -122,7 +199,17 @@ proc proxySpawnDecodeTask(
   data: ref seq[seq[byte]],
   parity: ref seq[seq[byte]]
 ): Flowvar[DecodeTaskResult] =
-  tp.spawn decodeTask(args, data[], parity[])
+  let h = hashOf(data)
+  echo "proxy hash of data " & h
+
+  let debug = h == "12209C9675C6D0F65E90554E4251EAA8B4F1DE46E8178FD885B98A607F127C64C5C3"
+
+  tp.spawn decodeTask(args, data[], parity[], debug)
+  # let res = DecodeTaskResult.newFlowVar
+
+  # res.readyWith(decodeTask(args, data[], parity[], debug))
+  # return res
+  
 
 proc awaitResult[T](signal: ThreadSignalPtr, handle: Flowvar[T]): Future[?!T] {.async.} =
   await wait(signal)
@@ -184,12 +271,17 @@ proc asyncDecode*(
   without signal =? ThreadSignalPtr.new().mapFailure, err:
     return failure(err)
 
+  echo "orig hash of data " & hashOf(data)
+  # echo "hash of parity " & hashOf(parity)
+
   try:
     let
       ecK = data[].len
       args = DecodeTaskArgs(signal: signal, backend: unsafeAddr backend, blockSize: blockSize, ecK: ecK)
       handle = proxySpawnDecodeTask(tp, args, data, parity)
 
+    # GC_fullCollect()
+
     without res =? await awaitResult(signal, handle), err:
       return failure(err)
 
@@ -201,6 +293,18 @@ proc asyncDecode*(
         recovered[i] = newSeq[byte](blockSize)
         copyMem(addr recovered[i][0], addr res.value.data[i * blockSize], blockSize)
 
+      # echo "orig hash of recovered " & hashOf(recovered)
+
+      var ptrs: seq[pointer]
+
+      for i in 0..<recovered[].len:
+        ptrs.add(unsafeAddr recovered[i][0])
+
+
+      # echo "unsafe hash of recovered" & unsafeHashOf(ptrs, recovered[].mapIt(it.len))
+
+      # echo "orig hash of parity " & hashOf(parity)
+
       deallocShared(res.value.data)
 
       return success(recovered)
@@ -209,3 +313,56 @@ proc asyncDecode*(
   finally:
     if err =? signal.close().mapFailure.errorOption():
       error "Error closing signal", msg = $err.msg
+
+proc syncDecode*(
+  tp: Taskpool,
+  backend: DecoderBackend,
+  data, parity: ref seq[seq[byte]],
+  blockSize: int
+): Future[?!ref seq[seq[byte]]] {.async.} =
+
+  let
+    ecK = data[].len
+  
+  var recovered = newSeqWith[seq[byte]](ecK, newSeq[byte](blockSize))
+
+  backend.decode(data[], parity[], recovered)
+
+  var recoveredRet = seq[seq[byte]].new()
+  recoveredRet[].setLen(ecK)
+
+  for i in 0..<recoveredRet[].len:
+    recoveredRet[i] = newSeq[byte](blockSize)
+    copyMem(addr recoveredRet[i][0], addr recovered[i][0], blockSize)
+
+  return success(recoveredRet)
+
+
+  # without signal =? ThreadSignalPtr.new().mapFailure, err:
+  #   return failure(err)
+
+  # try:
+  #   let
+  #     ecK = data[].len
+  #     args = DecodeTaskArgs(signal: signal, backend: unsafeAddr backend, blockSize: blockSize, ecK: ecK)
+  #     handle = proxySpawnDecodeTask(tp, args, data, parity)
+
+  #   without res =? await awaitResult(signal, handle), err:
+  #     return failure(err)
+
+  #   if res.isOk:
+  #     var recovered = seq[seq[byte]].new()
+  #     recovered[].setLen(ecK)
+
+  #     for i in 0..<recovered[].len:
+  #       recovered[i] = newSeq[byte](blockSize)
+  #       copyMem(addr recovered[i][0], addr res.value.data[i * blockSize], blockSize)
+
+  #     deallocShared(res.value.data)
+
+  #     return success(recovered)
+  #   else:
+  #     return failure($res.error)
+  # finally:
+  #   if err =? signal.close().mapFailure.errorOption():
+  #     error "Error closing signal", msg = $err.msg
diff --git a/codex/erasure/erasure.nim b/codex/erasure/erasure.nim
index 56e3e1cf..1b9ad68b 100644
--- a/codex/erasure/erasure.nim
+++ b/codex/erasure/erasure.nim
@@ -31,6 +31,8 @@ import ../errors
 
 import pkg/stew/byteutils
 
+import pkg/stew/io2
+
 import ./backend
 import ./asyncbackend
 
@@ -107,6 +109,50 @@ proc getPendingBlocks(
   ## Get pending blocks iterator
   ##
 
+  var
+    indiciesIter = Iter[int].new(indicies)
+    
+    pendingBlocks = mapAsync[int, (?!bt.Block, int)](indiciesIter, (i: int) =>
+      self.store.getBlock(
+        BlockAddress.init(manifest.treeCid, i)
+      ).map((r: ?!bt.Block) => (r, i)) # Get the data blocks (first K)
+    )
+
+
+  pendingBlocks
+
+proc getPendingBlocks2(
+  self: Erasure,
+  manifest: Manifest,
+  indicies: seq[int]): AsyncIter[(?!bt.Block, int)] =
+  ## Get pending blocks iterator
+  ##
+
+  let shift = indicies[0]
+
+  let newIndicies = @[0, 203, 196, 189, 182, 175, 168, 161, 154, 147, 140, 133, 126, 119, 112, 105, 98, 91, 84, 77].mapIt(it + shift)
+
+  var
+    indiciesIter = Iter[int].new(newIndicies)
+    # indiciesIter = Iter[int].new(indicies.filterIt((it mod 3) != 2))
+    # indiciesIter = Iter[int].new(@(@[indicies[29]] & indicies[5..<25]))
+
+    
+    pendingBlocks = mapAsync[int, (?!bt.Block, int)](indiciesIter, (i: int) =>
+      self.store.getBlock(
+        BlockAddress.init(manifest.treeCid, i)
+      ).map((r: ?!bt.Block) => (r, i)) # Get the data blocks (first K)
+    )
+
+  pendingBlocks
+
+proc getPendingBlocks3(
+  self: Erasure,
+  manifest: Manifest,
+  indicies: seq[int]): AsyncIter[(?!bt.Block, int)] =
+  ## Get pending blocks iterator
+  ##
+
   var
     # request blocks from the store
     pendingBlocks = indicies.map( (i: int) =>
@@ -190,6 +236,8 @@ proc prepareDecodingData(
   ## `emptyBlock` - the empty block to be used for padding
   ##
 
+  var recIndicies = newSeq[int]()
+
   let
     strategy = encoded.protectedStrategy.init(
       firstIndex = 0,
@@ -197,7 +245,7 @@ proc prepareDecodingData(
       iterations = encoded.steps
     )
     indicies = toSeq(strategy.getIndicies(step))
-    pendingBlocksIter = self.getPendingBlocks(encoded, indicies)
+    pendingBlocksIter = self.getPendingBlocks2(encoded, indicies)
 
   var
     dataPieces = 0
@@ -214,6 +262,8 @@ proc prepareDecodingData(
       trace "Failed retreiving a block", idx, treeCid = encoded.treeCid, msg = err.msg
       continue
 
+    recIndicies.add(idx)
+
     let
       pos = indexToPos(encoded.steps, idx, step)
 
@@ -236,6 +286,13 @@ proc prepareDecodingData(
 
     resolved.inc
 
+  let recCids = collect:
+    for i in recIndicies:
+      cids[i]
+
+  without recTree =? CodexTree.init(recCids), err:
+    return failure(err)
+
   return success (dataPieces.Natural, parityPieces.Natural)
 
 proc init*(
@@ -317,6 +374,7 @@ proc encodeData(
 
         trace "Adding parity block", cid = blk.cid, idx
         cids[idx] = blk.cid
+        io2.writeFile("parity_" & $idx, blk.data).get()
         if isErr (await self.store.putBlock(blk)):
           trace "Unable to store block!", cid = blk.cid
           return failure("Unable to store block!")
@@ -372,6 +430,47 @@ proc encode*(
 
   return success encodedManifest
 
+proc hashOf(bytes: ref seq[seq[byte]]): string =
+  var totalLen = 0
+  for i in 0..<len(bytes[]):
+    totalLen = totalLen + bytes[i].len
+
+  var buf = newSeq[byte]()
+
+  buf.setLen(totalLen)
+
+  var offset = 0
+  for i in 0..<len(bytes[]):
+    if bytes[i].len > 0:
+      copyMem(addr buf[offset], addr bytes[i][0], bytes[i].len)
+      offset = offset + bytes[i].len
+
+  let mhash = MultiHash.digest("sha2-256", buf).mapFailure()
+
+  return mhash.get().hex
+  # without mh =? mhash, err:
+  #   return "error " & err.msg
+
+  # return mh.hex
+
+# proc unsafeHashOf(bytes: seq[pointer], lens: seq[int]): string =
+#   var totalLen = 0
+#   for l in lens:
+#     totalLen = totalLen + l
+
+#   var buf = newSeq[byte]()
+
+#   buf.setLen(totalLen)
+
+#   var offset = 0
+#   for l in lens:
+#     if l > 0:
+#       copyMem(addr buf[offset], bytes[i], l)
+#       offset = offset + l
+
+#   let mhash = MultiHash.digest("sha2-256", buf)
+#   return $mhash
+
 proc decode*(
   self: Erasure,
   encoded: Manifest): Future[?!Manifest] {.async.} =
@@ -418,6 +517,10 @@ proc decode*(
         trace "Error decoding data", err = err.msg
         return failure(err)
 
+      echo "hash of recovered " & hashOf(recovered)
+
+      # GC_fullCollect()
+
       for i in 0..<encoded.ecK:
         let idx = i * encoded.steps + step
         if data[i].len <= 0 and not cids[idx].isEmpty:
diff --git a/generate-mb.sh b/generate-mb.sh
new file mode 100755
index 00000000..d84906da
--- /dev/null
+++ b/generate-mb.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+# Example - generating 64 MiB file
+# ./generate-mb.sh my_file.bin 64
+
+fname=$1
+size=$2
+
+dd if=/dev/urandom of="$fname" bs=1m count="$size"
diff --git a/tests/codex/helpers.nim b/tests/codex/helpers.nim
index 89aeafd1..b536867a 100644
--- a/tests/codex/helpers.nim
+++ b/tests/codex/helpers.nim
@@ -11,6 +11,8 @@ import pkg/codex/blockexchange
 import pkg/codex/rng
 import pkg/codex/utils
 
+import pkg/stew/io2
+
 import ./helpers/nodeutils
 import ./helpers/randomchunker
 import ./helpers/mockchunker
@@ -84,6 +86,8 @@ proc makeWantList*(
 proc storeDataGetManifest*(store: BlockStore, chunker: Chunker): Future[Manifest] {.async.} =
   var cids = newSeq[Cid]()
 
+  var i = 0
+
   while (
     let chunk = await chunker.getBytes();
     chunk.len > 0):
@@ -92,6 +96,10 @@ proc storeDataGetManifest*(store: BlockStore, chunker: Chunker): Future[Manifest
     cids.add(blk.cid)
     (await store.putBlock(blk)).tryGet()
 
+    io2.writeFile("block_" & $i, blk.data)
+
+    i.inc
+
   let
     tree = CodexTree.init(cids).tryGet()
     treeCid = tree.rootCid.tryGet()
diff --git a/tests/codex/rndtesterasure.nim b/tests/codex/rndtesterasure.nim
new file mode 100644
index 00000000..e4abae2f
--- /dev/null
+++ b/tests/codex/rndtesterasure.nim
@@ -0,0 +1,64 @@
+import std/sequtils
+import std/sugar
+import std/cpuinfo
+
+import pkg/chronos
+import pkg/datastore
+import pkg/questionable/results
+
+import pkg/codex/erasure
+import pkg/codex/manifest
+import pkg/codex/stores
+import pkg/codex/blocktype as bt
+import pkg/codex/utils
+import pkg/codex/chunker
+import pkg/taskpools
+
+import ../asynctest
+import ./helpers
+
+suite "Erasure encode/decode":
+  var store: BlockStore
+  var erasure: Erasure
+  var taskpool: Taskpool
+  let repoTmp = TempLevelDb.new()
+  let metaTmp = TempLevelDb.new()
+
+  setup:
+    let
+      repoDs = repoTmp.newDb()
+      metaDs = metaTmp.newDb()
+
+    store = RepoStore.new(repoDs, metaDs)
+    taskpool = Taskpool.new(num_threads = countProcessors())
+    erasure = Erasure.new(store, leoEncoderProvider, leoDecoderProvider, taskpool)
+
+  teardown:
+    await repoTmp.destroyDb()
+    await metaTmp.destroyDb()
+
+  test "Should encode/decode a file":
+    let blockSize = 16.KiBs
+    # for blockSize in @(1..<8).mapIt(it * 1024):
+    # echo $blockSize
+
+    let 
+      file = open("test_file.bin")
+      chunker = FileChunker.new(file = file, chunkSize = blockSize)
+
+
+    let 
+      k = 20.Natural
+      m = 10.Natural
+    
+    let manifest = await storeDataGetManifest(store, chunker)
+
+    let encoded = (await erasure.encode(manifest, k, m)).tryGet()
+
+    let decoded = (await erasure.decode(encoded)).tryGet()
+
+    check:
+      decoded.treeCid == manifest.treeCid
+      decoded.treeCid == encoded.originalTreeCid
+      decoded.blocksCount == encoded.originalBlocksCount
+
diff --git a/tests/codex/slots/testprover.nim b/tests/codex/slots/testprover.nim
index 179047f3..22d01edf 100644
--- a/tests/codex/slots/testprover.nim
+++ b/tests/codex/slots/testprover.nim
@@ -69,7 +69,24 @@ suite "Test Prover":
       circomBackend = CircomCompat.init(r1cs, wasm)
       prover = Prover.new(store, circomBackend, samples)
       challenge = 1234567.toF.toBytes.toArray32
-      (inputs, proof) = (await prover.prove(1, verifiable, challenge)).tryGet
+
+    proc someFut(): Future[void] {.async.} =
+      echo "before 100 millis"
+      await sleepAsync(100.millis)
+      echo "after 100 millis"
+
+    asyncSpawn(someFut())
+
+    echo "started proving"
+    let  (inputs, proof) = (await prover.prove(1, verifiable, challenge)).tryGet
+    echo "finished proving"
+
+    await sleepAsync(10.millis)
+    echo "after additional 10 millis"
+    await sleepAsync(300.millis)
+    echo "after additional 300 millis"
 
     check:
       (await prover.verify(proof, inputs)).tryGet == true
+
+