diff --git a/backend/onedrive/quickxorhash/quickxorhash.go b/backend/onedrive/quickxorhash/quickxorhash.go
new file mode 100644
index 000000000..7fb1bbe07
--- /dev/null
+++ b/backend/onedrive/quickxorhash/quickxorhash.go
@@ -0,0 +1,203 @@
+// Package quickxorhash provides the quickXorHash algorithm which is a
+// quick, simple non-cryptographic hash algorithm that works by XORing
+// the bytes in a circular-shifting fashion.
+//
+// It is used by Microsoft Onedrive for Business to hash data.
+//
+// See: https://docs.microsoft.com/en-us/onedrive/developer/code-snippets/quickxorhash
+package quickxorhash
+
+// This code was ported from the code snippet linked from
+// https://docs.microsoft.com/en-us/onedrive/developer/code-snippets/quickxorhash
+// Which has the copyright
+
+// ------------------------------------------------------------------------------
+//  Copyright (c) 2016 Microsoft Corporation
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in
+//  all copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+//  THE SOFTWARE.
+// ------------------------------------------------------------------------------
+
+import (
+	"hash"
+)
+
+const (
+	// BlockSize is the preferred size for hashing
+	BlockSize = 64
+	// Size of the output checksum
+	Size           = 20
+	bitsInLastCell = 32
+	shift          = 11
+	threshold      = 600
+	widthInBits    = 8 * Size
+	dataSize       = (widthInBits-1)/64 + 1
+)
+
+type quickXorHash struct {
+	data        [dataSize]uint64
+	lengthSoFar uint64
+	shiftSoFar  int
+}
+
+// New returns a new hash.Hash computing the quickXorHash checksum.
+func New() hash.Hash {
+	return &quickXorHash{}
+}
+
+// Write (via the embedded io.Writer interface) adds more data to the running hash.
+// It never returns an error.
+//
+// Write writes len(p) bytes from p to the underlying data stream. It returns
+// the number of bytes written from p (0 <= n <= len(p)) and any error
+// encountered that caused the write to stop early. Write must return a non-nil
+// error if it returns n < len(p). Write must not modify the slice data, even
+// temporarily.
+//
+// Implementations must not retain p.
+func (q *quickXorHash) Write(p []byte) (n int, err error) {
+	currentshift := q.shiftSoFar
+
+	// The bitvector where we'll start xoring
+	vectorArrayIndex := currentshift / 64
+
+	// The position within the bit vector at which we begin xoring
+	vectorOffset := currentshift % 64
+	iterations := len(p)
+	if iterations > widthInBits {
+		iterations = widthInBits
+	}
+
+	for i := 0; i < iterations; i++ {
+		isLastCell := vectorArrayIndex == len(q.data)-1
+		var bitsInVectorCell int
+		if isLastCell {
+			bitsInVectorCell = bitsInLastCell
+		} else {
+			bitsInVectorCell = 64
+		}
+
+		// There's at least 2 bitvectors before we reach the end of the array
+		if vectorOffset <= bitsInVectorCell-8 {
+			for j := i; j < len(p); j += widthInBits {
+				q.data[vectorArrayIndex] ^= uint64(p[j]) << uint(vectorOffset)
+			}
+		} else {
+			index1 := vectorArrayIndex
+			var index2 int
+			if isLastCell {
+				index2 = 0
+			} else {
+				index2 = vectorArrayIndex + 1
+			}
+			low := byte(bitsInVectorCell - vectorOffset)
+
+			xoredByte := byte(0)
+			for j := i; j < len(p); j += widthInBits {
+				xoredByte ^= p[j]
+			}
+			q.data[index1] ^= uint64(xoredByte) << uint(vectorOffset)
+			q.data[index2] ^= uint64(xoredByte) >> low
+		}
+		vectorOffset += shift
+		for vectorOffset >= bitsInVectorCell {
+			if isLastCell {
+				vectorArrayIndex = 0
+			} else {
+				vectorArrayIndex = vectorArrayIndex + 1
+			}
+			vectorOffset -= bitsInVectorCell
+		}
+	}
+
+	// Update the starting position in a circular shift pattern
+	q.shiftSoFar = (q.shiftSoFar + shift*(len(p)%widthInBits)) % widthInBits
+
+	q.lengthSoFar += uint64(len(p))
+
+	return len(p), nil
+}
+
+// Calculate the current checksum
+func (q *quickXorHash) checkSum() (h [Size]byte) {
+	// Output the data as little endian bytes
+	ph := 0
+	for _, d := range q.data[:len(q.data)-1] {
+		_ = h[ph+7] // bounds check
+		h[ph+0] = byte(d >> (8 * 0))
+		h[ph+1] = byte(d >> (8 * 1))
+		h[ph+2] = byte(d >> (8 * 2))
+		h[ph+3] = byte(d >> (8 * 3))
+		h[ph+4] = byte(d >> (8 * 4))
+		h[ph+5] = byte(d >> (8 * 5))
+		h[ph+6] = byte(d >> (8 * 6))
+		h[ph+7] = byte(d >> (8 * 7))
+		ph += 8
+	}
+	// remaining 32 bits
+	d := q.data[len(q.data)-1]
+	h[Size-4] = byte(d >> (8 * 0))
+	h[Size-3] = byte(d >> (8 * 1))
+	h[Size-2] = byte(d >> (8 * 2))
+	h[Size-1] = byte(d >> (8 * 3))
+
+	// XOR the file length with the least significant bits in little endian format
+	d = q.lengthSoFar
+	h[Size-8] ^= byte(d >> (8 * 0))
+	h[Size-7] ^= byte(d >> (8 * 1))
+	h[Size-6] ^= byte(d >> (8 * 2))
+	h[Size-5] ^= byte(d >> (8 * 3))
+	h[Size-4] ^= byte(d >> (8 * 4))
+	h[Size-3] ^= byte(d >> (8 * 5))
+	h[Size-2] ^= byte(d >> (8 * 6))
+	h[Size-1] ^= byte(d >> (8 * 7))
+
+	return h
+}
+
+// Sum appends the current hash to b and returns the resulting slice.
+// It does not change the underlying hash state.
+func (q *quickXorHash) Sum(b []byte) []byte {
+	hash := q.checkSum()
+	return append(b, hash[:]...)
+}
+
+// Reset resets the Hash to its initial state.
+func (q *quickXorHash) Reset() {
+	*q = quickXorHash{}
+}
+
+// Size returns the number of bytes Sum will return.
+func (q *quickXorHash) Size() int {
+	return Size
+}
+
+// BlockSize returns the hash's underlying block size.
+// The Write method must be able to accept any amount
+// of data, but it may operate more efficiently if all writes
+// are a multiple of the block size.
+func (q *quickXorHash) BlockSize() int {
+	return BlockSize
+}
+
+// Sum returns the quickXorHash checksum of the data.
+func Sum(data []byte) [Size]byte {
+	var d quickXorHash
+	_, _ = d.Write(data)
+	return d.checkSum()
+}
diff --git a/backend/onedrive/quickxorhash/quickxorhash_test.go b/backend/onedrive/quickxorhash/quickxorhash_test.go
new file mode 100644
index 000000000..94562af2c
--- /dev/null
+++ b/backend/onedrive/quickxorhash/quickxorhash_test.go
@@ -0,0 +1,168 @@
+package quickxorhash
+
+import (
+	"encoding/base64"
+	"fmt"
+	"hash"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+var testVectors = []struct {
+	size int
+	in   string
+	out  string
+}{
+	{0, ``, "AAAAAAAAAAAAAAAAAAAAAAAAAAA="},
+	{1, `Sg==`, "SgAAAAAAAAAAAAAAAQAAAAAAAAA="},
+	{2, `tbQ=`, "taAFAAAAAAAAAAAAAgAAAAAAAAA="},
+	{3, `0pZP`, "0rDEEwAAAAAAAAAAAwAAAAAAAAA="},
+	{4, `jRRDVA==`, "jaDAEKgAAAAAAAAABAAAAAAAAAA="},
+	{5, `eAV52qE=`, "eChAHrQRCgAAAAAABQAAAAAAAAA="},
+	{6, `luBZlaT6`, "lgBHFipBCn0AAAAABgAAAAAAAAA="},
+	{7, `qaApEj66lw==`, "qQBFCiTgA11cAgAABwAAAAAAAAA="},
+	{8, `/aNzzCFPS/A=`, "/RjFHJgRgicsAR4ACAAAAAAAAAA="},
+	{9, `n6Neh7p6fFgm`, "nxiFFw6hCz3wAQsmCQAAAAAAAAA="},
+	{10, `J9iPGCbfZSTNyw==`, "J8DGIzBggm+UgQTNUgYAAAAAAAA="},
+	{11, `i+UZyUGJKh+ISbk=`, "iyhHBpIRhESo4AOIQ0IuAAAAAAA="},
+	{12, `h490d57Pqz5q2rtT`, "h3gEHe7giWeswgdq3MYupgAAAAA="},
+	{13, `vPgoDjOfO6fm71RxLw==`, "vMAHChwwg0/s4BTmdQcV4vACAAA="},
+	{14, `XoJ1AsoR4fDYJrDqYs4=`, "XhBEHQSgjAiEAx7YPgEs1CEGZwA="},
+	{15, `gQaybEqS/4UlDc8e4IJm`, "gDCALNigBEn8oxAlZ8AzPAAOQZg="},
+	{16, `2fuxhBJXtpWFe8dOfdGeHw==`, "O9tHLAghgSvYohKFyMMxnNCHaHg="},
+	{17, `XBV6YKU9V7yMakZnFIxIkuU=`, "HbplHsBQih5cgReMQYMRzkABRiA="},
+	{18, `XJZSOiNO2bmfKnTKD7fztcQX`, "/6ZArHQwAidkIxefQgEdlPGAW8w="},
+	{19, `g8VtAh+2Kf4k0kY5tzji2i2zmA==`, "wDNrgwHWAVukwB8kg4YRcnALHIg="},
+	{20, `T6LYJIfDh81JrAK309H2JMJTXis=`, "zBTHrspn3mEcohlJdIUAbjGNaNg="},
+	{21, `DWAAX5/CIfrmErgZa8ot6ZraeSbu`, "LR2Z0PjuRYGKQB/mhQAuMrAGZbQ="},
+	{22, `N9abi3qy/mC1THZuVLHPpx7SgwtLOA==`, "1KTYttCBEen8Hwy1doId3ECFWDw="},
+	{23, `LlUe7wHerLqEtbSZLZgZa9u0m7hbiFs=`, "TqVZpxs3cN61BnuFvwUtMtECTGQ="},
+	{24, `bU2j/0XYdgfPFD4691jV0AOUEUPR4Z5E`, "bnLBiLpVgnxVkXhNsIAPdHAPLFQ="},
+	{25, `lScPwPsyUsH2T1Qsr31wXtP55Wqbe47Uyg==`, "VDMSy8eI26nBHCB0e8gVWPCKPsA="},
+	{26, `rJaKh1dLR1k+4hynliTZMGf8Nd4qKKoZiAM=`, "r7bjwkl8OYQeNaMcCY8fTmEJEmQ="},
+	{27, `pPsT0CPmHrd3Frsnva1pB/z1ytARLeHEYRCo`, "Rdg7rCcDomL59pL0s6GuTvqLVqQ="},
+	{28, `wSRChaqmrsnMrfB2yqI43eRWbro+f9kBvh+01w==`, "YTtloIi6frI7HX3vdLvE7I2iUOA="},
+	{29, `apL67KMIRxQeE9k1/RuW09ppPjbF1WeQpTjSWtI=`, "CIpedls+ZlSQ654fl+X26+Q7LVU="},
+	{30, `53yx0/QgMTVb7OOzHRHbkS7ghyRc+sIXxi7XHKgT`, "zfJtLGFgR9DB3Q64fAFIp+S5iOY="},
+	{31, `PwXNnutoLLmxD8TTog52k8cQkukmT87TTnDipKLHQw==`, "PTaGs7yV3FUyBy/SfU6xJRlCJlI="},
+	{32, `NbYXsp5/K6mR+NmHwExjvWeWDJFnXTKWVlzYHoesp2E=`, "wjuAuWDiq04qDt1R8hHWDDcwVoQ="},
+	{33, `qQ70RB++JAR5ljNv3lJt1PpqETPsckopfonItu18Cr3E`, "FkJaeg/0Z5+euShYlLpE2tJh+Lo="},
+	{34, `RhzSatQTQ9/RFvpHyQa1WLdkr3nIk6MjJUma998YRtp44A==`, "SPN2D29reImAqJezlqV2DLbi8tk="},
+	{35, `DND1u1uZ5SqZVpRUk6NxSUdVo7IjjL9zs4A1evDNCDLcXWc=`, "S6lBk2hxI2SWBfn7nbEl7D19UUs="},
+	{36, `jEi62utFz69JMYHjg1iXy7oO6ZpZSLcVd2B+pjm6BGsv/CWi`, "s0lYU9tr/bp9xsnrrjYgRS5EvV8="},
+	{37, `hfS3DZZnhy0hv7nJdXLv/oJOtIgAuP9SInt/v8KeuO4/IvVh4A==`, "CV+HQCdd2A/e/vdi12f2UU55GLA="},
+	{38, `EkPQAC6ymuRrYjIXD/LT/4Vb+7aTjYVZOHzC8GPCEtYDP0+T3Nc=`, "kE9H9sEmr3vHBYUiPbvsrcDgSEo="},
+	{39, `vtBOGIENG7yQ/N7xNWPNIgy66Gk/I2Ur/ZhdFNUK9/1FCZuu/KeS`, "+Fgp3HBimtCzUAyiinj3pkarYTk="},
+	{40, `YnF4smoy9hox2jBlJ3VUa4qyCRhOZbWcmFGIiszTT4zAdYHsqJazyg==`, "arkIn+ELddmE8N34J9ydyFKW+9w="},
+	{41, `0n7nl3YJtipy6yeUbVPWtc2h45WbF9u8hTz5tNwj3dZZwfXWkk+GN3g=`, "YJLNK7JR64j9aODWfqDvEe/u6NU="},
+	{42, `FnIIPHayc1pHkY4Lh8+zhWwG8xk6Knk/D3cZU1/fOUmRAoJ6CeztvMOL`, "22RPOylMtdk7xO/QEQiMli4ql0k="},
+	{43, `J82VT7ND0Eg1MorSfJMUhn+qocF7PsUpdQAMrDiHJ2JcPZAHZ2nyuwjoKg==`, "pOR5eYfwCLRJbJsidpc1rIJYwtM="},
+	{44, `Zbu+78+e35ZIymV5KTDdub5McyI3FEO8fDxs62uWHQ9U3Oh3ZqgaZ30SnmQ=`, "DbvbTkgNTgWRqRidA9r1jhtUjro="},
+	{45, `lgybK3Da7LEeY5aeeNrqcdHvv6mD1W4cuQ3/rUj2C/CNcSI0cAMw6vtpVY3y`, "700RQByn1lRQSSme9npQB/Ye+bY="},
+	{46, `jStZgKHv4QyJLvF2bYbIUZi/FscHALfKHAssTXkrV1byVR9eACwW9DNZQRHQwg==`, "uwN55He8xgE4g93dH9163xPew4U="},
+	{47, `V1PSud3giF5WW72JB/bgtltsWtEB5V+a+wUALOJOGuqztzVXUZYrvoP3XV++gM0=`, "U+3ZfUF/6mwOoHJcSHkQkckfTDA="},
+	{48, `VXs4t4tfXGiWAL6dlhEMm0YQF0f2w9rzX0CvIVeuW56o6/ec2auMpKeU2VeteEK5`, "sq24lSf7wXLH8eigHl07X+qPTps="},
+	{49, `bLUn3jLH+HFUsG3ptWTHgNvtr3eEv9lfKBf0jm6uhpqhRwtbEQ7Ovj/hYQf42zfdtQ==`, "uC8xrnopGiHebGuwgq607WRQyxQ="},
+	{50, `4SVmjtXIL8BB8SfkbR5Cpaljm2jpyUfAhIBf65XmKxHlz9dy5XixgiE/q1lv+esZW/E=`, "wxZ0rxkMQEnRNAp8ZgEZLT4RdLM="},
+	{51, `pMljctlXeFUqbG3BppyiNbojQO3ygg6nZPeUZaQcVyJ+Clgiw3Q8ntLe8+02ZSfyCc39`, "aZEPmNvOXnTt7z7wt+ewV7QGMlg="},
+	{52, `C16uQlxsHxMWnV2gJhFPuJ2/guZ4N1YgmNvAwL1yrouGQtwieGx8WvZsmYRnX72JnbVtTw==`, "QtlSNqXhVij64MMhKJ3EsDFB/z8="},
+	{53, `7ZVDOywvrl3L0GyKjjcNg2CcTI81n2CeUbzdYWcZOSCEnA/xrNHpiK01HOcGh3BbxuS4S6g=`, "4NznNJc4nmXeApfiCFTq/H5LbHw="},
+	{54, `JXm2tTVqpYuuz2Cc+ZnPusUb8vccPGrzWK2oVwLLl/FjpFoxO9FxGlhnB08iu8Q/XQSdzHn+`, "IwE5+2pKNcK366I2k2BzZYPibSI="},
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+	{128, `ikwCorI7PKWz17EI50jZCGbV9JU2E8bXVfxNMg5zdmqSZ2NlsQPp0kqYIPjzwTg1MBtfWPg53k0h
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+c/RNRCQTAfZbnf2QwV7sluw4fH3XJr07UoD0YqN+7XZzidtrwqMY26fpLZnyZjnBEt1FAZWO7RnK
+G5asg8xRk9YaDdedXdQSJAOy6bWEWlABj+tVAigBxavaluUH8LOj+yfCFldJjNLdi90fVHkUD/m4
+Mr5OtmupNMXPwuG3EQlqWUVpQoYpUYKLsk7a5Mvg6UFkiH596y5IbJEVCI1Kb3D1`, "e3+wo77iKcILiZegnzyUNcjCdoQ="},
+}
+
+func TestQuickXorHash(t *testing.T) {
+	for _, test := range testVectors {
+		what := fmt.Sprintf("test size %d", test.size)
+		in, err := base64.StdEncoding.DecodeString(test.in)
+		require.NoError(t, err, what)
+		got := Sum(in)
+		want, err := base64.StdEncoding.DecodeString(test.out)
+		require.NoError(t, err, what)
+		assert.Equal(t, want, got[:], what)
+	}
+}
+
+func TestQuickXorHashByBlock(t *testing.T) {
+	for _, blockSize := range []int{1, 2, 4, 7, 8, 16, 32, 64, 128, 256, 512} {
+		for _, test := range testVectors {
+			what := fmt.Sprintf("test size %d blockSize %d", test.size, blockSize)
+			in, err := base64.StdEncoding.DecodeString(test.in)
+			require.NoError(t, err, what)
+			h := New()
+			for i := 0; i < len(in); i += blockSize {
+				end := i + blockSize
+				if end > len(in) {
+					end = len(in)
+				}
+				n, err := h.Write(in[i:end])
+				require.Equal(t, end-i, n, what)
+				require.NoError(t, err, what)
+			}
+			got := h.Sum(nil)
+			want, err := base64.StdEncoding.DecodeString(test.out)
+			require.NoError(t, err, what)
+			assert.Equal(t, want, got[:], test.size, what)
+		}
+	}
+}
+
+func TestSize(t *testing.T) {
+	d := New()
+	assert.Equal(t, 20, d.Size())
+}
+
+func TestBlockSize(t *testing.T) {
+	d := New()
+	assert.Equal(t, 64, d.BlockSize())
+}
+
+func TestReset(t *testing.T) {
+	d := New()
+	zeroHash := d.Sum(nil)
+	_, _ = d.Write([]byte{1})
+	assert.NotEqual(t, zeroHash, d.Sum(nil))
+	d.Reset()
+	assert.Equal(t, zeroHash, d.Sum(nil))
+}
+
+// check interface
+var _ hash.Hash = (*quickXorHash)(nil)