diff --git a/pkg/vm/bigint.go b/pkg/vm/bigint.go
new file mode 100644
index 000000000..a99fbf383
--- /dev/null
+++ b/pkg/vm/bigint.go
@@ -0,0 +1,137 @@
+package vm
+
+import (
+	"encoding/binary"
+	"math/big"
+	"math/bits"
+)
+
+// wordSizeBytes is a size of a big.Word (uint) in bytes.`
+const wordSizeBytes = bits.UintSize / 8
+
+// bytesToInt converts data in little-endian format to
+// an integer.
+func bytesToInt(data []byte) *big.Int {
+	n := new(big.Int)
+	size := len(data)
+	if size == 0 {
+		return big.NewInt(0)
+	}
+
+	isNeg := data[size-1]&0x80 != 0
+
+	size = getEffectiveSize(data, isNeg)
+	if size == 0 {
+		if isNeg {
+			return big.NewInt(-1)
+		}
+
+		return big.NewInt(0)
+	}
+
+	lw := size / wordSizeBytes
+	ws := make([]big.Word, lw+1)
+	for i := 0; i < lw; i++ {
+		base := i * wordSizeBytes
+		for j := base + 7; j >= base; j-- {
+			ws[i] <<= 8
+			ws[i] ^= big.Word(data[j])
+		}
+	}
+
+	for i := size - 1; i >= lw*wordSizeBytes; i-- {
+		ws[lw] <<= 8
+		ws[lw] ^= big.Word(data[i])
+	}
+
+	if isNeg {
+		for i := 0; i <= lw; i++ {
+			ws[i] = ^ws[i]
+		}
+
+		shift := byte(wordSizeBytes-size%wordSizeBytes) * 8
+		ws[lw] = ws[lw] & (^big.Word(0) >> shift)
+
+		n.SetBits(ws)
+		n.Neg(n)
+
+		return n.Sub(n, big.NewInt(1))
+	}
+
+	return n.SetBits(ws)
+}
+
+// getEffectiveSize returns minimal number of bytes required
+// to represent a number (two's complement for negatives).
+func getEffectiveSize(buf []byte, isNeg bool) int {
+	var b byte
+	if isNeg {
+		b = 0xFF
+	}
+
+	size := len(buf)
+	for ; size > 0; size-- {
+		if buf[size-1] != b {
+			break
+		}
+	}
+
+	return size
+}
+
+// intToBytes converts integer to a slice in little-endian format.
+func intToBytes(n *big.Int) []byte {
+	sign := n.Sign()
+	if sign == 0 {
+		return []byte{0}
+	}
+
+	var ws []big.Word
+	if sign == 1 {
+		ws = n.Bits()
+	} else {
+		n1 := new(big.Int).Add(n, big.NewInt(1))
+		if n1.Sign() == 0 { // n == -1
+			return []byte{0xFF}
+		}
+
+		ws = n1.Bits()
+	}
+
+	data := wordsToBytes(ws)
+
+	size := len(data)
+	for ; data[size-1] == 0; size-- {
+	}
+
+	data = data[:size]
+
+	if data[size-1]&0x80 != 0 {
+		data = append(data, 0)
+	}
+
+	if sign == -1 {
+		for i := range data {
+			data[i] = ^data[i]
+		}
+	}
+
+	return data
+}
+
+func wordsToBytes(ws []big.Word) []byte {
+	lb := len(ws) * wordSizeBytes
+	bs := make([]byte, lb, lb+1)
+
+	if wordSizeBytes == 8 {
+		for i := range ws {
+			binary.LittleEndian.PutUint64(bs[i*wordSizeBytes:], uint64(ws[i]))
+		}
+	} else {
+		for i := range ws {
+			binary.LittleEndian.PutUint32(bs[i*wordSizeBytes:], uint32(ws[i]))
+		}
+	}
+
+	return bs
+}
diff --git a/pkg/vm/bigint_test.go b/pkg/vm/bigint_test.go
new file mode 100644
index 000000000..4554875b5
--- /dev/null
+++ b/pkg/vm/bigint_test.go
@@ -0,0 +1,185 @@
+package vm
+
+import (
+	"math"
+	"math/big"
+	"testing"
+
+	"github.com/CityOfZion/neo-go/pkg/util"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// testCases were generated using C# node
+// https://dotnetfiddle.net/trQ4xt
+var testCases = []struct {
+	number int64
+	buf    []byte
+}{
+	{0, []byte{0}},
+	{1, []byte{1}},
+	{-1, []byte{255}},
+	{2, []byte{2}},
+	{-2, []byte{254}},
+	{127, []byte{127}},
+	{-127, []byte{129}},
+	{128, []byte{128, 0}},
+	{-128, []byte{128}},
+	{129, []byte{129, 0}},
+	{-129, []byte{127, 255}},
+	{255, []byte{255, 0}},
+	{-255, []byte{1, 255}},
+	{256, []byte{0, 1}},
+	{-256, []byte{0, 255}},
+	{123456789, []byte{21, 205, 91, 7}},
+	{-123456789, []byte{235, 50, 164, 248}},
+	{-6777216, []byte{128, 150, 152}}, // tx c8ba2ce29e07447639b9b658db3930c4cce617652d325e78b768ee9d4dbd72b8
+	{6777216, []byte{128, 105, 103}},
+
+	{32639, []byte{127, 127}},
+	{-32641, []byte{127, 128}},
+	{8355711, []byte{127, 127, 127}},
+	{-8355969, []byte{127, 127, 128}},
+	{2139062143, []byte{127, 127, 127, 127}},
+	{-2139127937, []byte{127, 127, 127, 128}},
+	{547599908735, []byte{127, 127, 127, 127, 127}},
+	{-547616751745, []byte{127, 127, 127, 127, 128}},
+	{140185576636287, []byte{127, 127, 127, 127, 127, 127}},
+	{-140189888446593, []byte{127, 127, 127, 127, 127, 128}},
+	{35887507618889599, []byte{127, 127, 127, 127, 127, 127, 127}},
+	{-35888611442327681, []byte{127, 127, 127, 127, 127, 127, 128}},
+	{9187201950435737471, []byte{127, 127, 127, 127, 127, 127, 127, 127}},
+	{-9187484529235886209, []byte{127, 127, 127, 127, 127, 127, 127, 128}},
+
+	// https://github.com/dotnet/runtime/blob/master/src/libraries/System.Runtime.Numerics/tests/BigInteger/ToByteArray.cs#L14
+	{0, []byte{0x00}},
+	{3, []byte{0x03}},
+	{128, []byte{0x80, 0x00}},
+	{200, []byte{0xc8, 0x00}},
+	{256, []byte{0x00, 0x01}},
+	{2005, []byte{0xd5, 0x07}},
+	{10197, []byte{0xd5, 0x27}},
+	{33023, []byte{0xff, 0x80, 0x00}},
+	{2368349, []byte{0x5d, 0x23, 0x24}},
+	{10756957, []byte{0x5d, 0x23, 0xa4, 0x00}},
+	{193100307, []byte{0x13, 0x7a, 0x82, 0x0b}},
+	{1266842131, []byte{0x13, 0x7a, 0x82, 0x4b}},
+	{math.MaxInt32, []byte{0xff, 0xff, 0xff, 0x7f}},
+	{-1, []byte{0xff}},
+	{-128, []byte{0x80}},
+	{-172, []byte{0x54, 0xff}},
+	{-23439, []byte{0x71, 0xa4}},
+	{-51301, []byte{0x9b, 0x37, 0xff}},
+	{-126341, []byte{0x7b, 0x12, 0xfe}},
+	{-13194515, []byte{0xed, 0xaa, 0x36, 0xff}},
+	{-2068145902, []byte{0x12, 0x99, 0xba, 0x84}},
+	{math.MinInt32, []byte{0x00, 0x00, 0x00, 0x80}},
+
+	// https://github.com/dotnet/runtime/blob/master/src/libraries/System.Runtime.Numerics/tests/BigInteger/ToByteArray.cs#L53
+	{0x100112233, []byte{0x33, 0x22, 0x11, 0x00, 0x01}},
+	{0x300112233, []byte{0x33, 0x22, 0x11, 0x00, 0x03}},
+	{0x8000112233, []byte{0x33, 0x22, 0x11, 0x00, 0x80, 0x00}},
+	{0x3cd00112233, []byte{0x33, 0x22, 0x11, 0x00, 0xcd, 0x03}},
+	{0xf92100112233, []byte{0x33, 0x22, 0x11, 0x00, 0x21, 0xf9, 0x00}},
+	{0x749aa00112233, []byte{0x33, 0x22, 0x11, 0x00, 0xaa, 0x49, 0x07}},
+	{0x80112200112233, []byte{0x33, 0x22, 0x11, 0x00, 0x22, 0x11, 0x80, 0x00}},
+	{0x7654321000112233, []byte{0x33, 0x22, 0x11, 0x00, 0x10, 0x32, 0x54, 0x76}},
+	{math.MaxInt64, []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f}},
+	{-0x100112233, []byte{0xcd, 0xdd, 0xee, 0xff, 0xfe}},
+	{-0x8000112233, []byte{0xcd, 0xdd, 0xee, 0xff, 0x7f, 0xff}},
+	{-0x3cd00112233, []byte{0xcd, 0xdd, 0xee, 0xff, 0x32, 0xfc}},
+	{-0xf92100112233, []byte{0xcd, 0xdd, 0xee, 0xff, 0xde, 0x06, 0xff}},
+	{-0x749aa00112233, []byte{0xcd, 0xdd, 0xee, 0xff, 0x55, 0xb6, 0xf8}},
+	{-0x80112200112233, []byte{0xcd, 0xdd, 0xee, 0xff, 0xdd, 0xee, 0x7f, 0xff}},
+	{-0x7654321000112233, []byte{0xcd, 0xdd, 0xee, 0xff, 0xef, 0xcd, 0xab, 0x89}},
+	{math.MinInt64, []byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80}},
+	{-0x100000000, []byte{0x00, 0x00, 0x00, 0x00, 0xff}},
+	{-0x300000000, []byte{0x00, 0x00, 0x00, 0x00, 0xfd}},
+	{-0x8000000000, []byte{0x00, 0x00, 0x00, 0x00, 0x80}},
+	{-0xfe00000000, []byte{0x00, 0x00, 0x00, 0x00, 0x02, 0xff}},
+	{-0xff00000000, []byte{0x00, 0x00, 0x00, 0x00, 0x01, 0xff}},
+	{-0xfeff00000000, []byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0xff}},
+	{-0xffff00000000, []byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0xff}},
+	{-0xfeffff00000000, []byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0xff}},
+	{-0xffffff00000000, []byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0xff}},
+}
+
+func TestIntToBytes(t *testing.T) {
+	for _, tc := range testCases {
+		buf := intToBytes(big.NewInt(tc.number))
+		assert.Equal(t, tc.buf, buf, "error while converting %d", tc.number)
+	}
+}
+
+func TestBytesToInt(t *testing.T) {
+	for _, tc := range testCases {
+		num := bytesToInt(tc.buf)
+		assert.Equal(t, tc.number, num.Int64(), "error while converting %d", tc.number)
+	}
+
+	t.Run("empty array", func(t *testing.T) {
+		require.EqualValues(t, 0, bytesToInt([]byte{}).Int64())
+	})
+}
+
+func TestEquivalentRepresentations(t *testing.T) {
+	for _, tc := range testCases {
+		buf := tc.buf
+		if tc.number >= 0 {
+			buf = append(buf, 0, 0, 0)
+		} else {
+			buf = append(buf, 0xFF, 0xFF, 0xFF)
+		}
+
+		num := bytesToInt(buf)
+		assert.Equal(t, tc.number, num.Int64(), "error while converting %d", tc.number)
+	}
+}
+
+var stringCases = []struct {
+	numStr string
+	buf    []byte
+}{
+	{"-1256271214286163627607479687759920896", []byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 255}},
+	{"168884912246183068104079824028124185087", []byte{255, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 127}},
+	{"1402184777283668118200134432800768511", []byte{255, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 1}},
+	{"-43536131589161850832973096317989605473920", []byte{128, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 128}},
+	{"43235871975677457350187428577111288447360", []byte{128, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 127}},
+}
+
+// this cases are from stdlib
+// https://github.com/dotnet/runtime/blob/master/src/libraries/System.Runtime.Numerics/tests/BigInteger/ToByteArray.cs#L96
+// note that they are in big-endian
+var stdlibCases = []struct {
+	numStr string
+	buf    []byte
+}{
+	{"0", []byte{0}},
+	{"127", []byte{0x7F}},
+	{"128", []byte{0x00, 0x80}},
+	{"33022", []byte{0x00, 0x80, 0xFE}},
+	{"-32514", []byte{0x80, 0xFE}},
+	{"-18374686475376656384", []byte{0xff, 0x01, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00}},
+	{"-18446744069414584320", []byte{0xff, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00}},
+	{"12364093636075302621581796971036731159910277399901099375861080574506898189967563102391591201943540153492149033597384108294298661111799425262742266671957323486506857011293831406641316917374615487590434666756862524718179898130435474398176187353530443750986128762955255137790631223519091107256083370837751230886741470719554141609004126665185940207631783192780186624919167901565253877397154522582982120840364212333366972597473045167409184762879376102731157263235904816835054250885637739932914015117504485702897712016943555929710070193511128651378003670520306509417025958556935067307123832592173743652726898616663215056178200135054604939862749863002480827458494339065850786495122398411385446068167146399066035389699059499954747263948595492570959736940353095030589033792026029085438901525807032848103038290802923997216273712349905230080849822000411239032166420681788646737098078876258256753058713515144604794792139863186822520361187685685356628044518258989638970651859178568755065879235553215218267011024902142765549091793970027321040036512883269922219608216030987714165823965404563131018846411947569009598716649463301689241563037584803938711917477764863093448004918315253652379776337794243677630540042379049027", []byte{0x00, 0xf0, 0x1d, 0x7b, 0xa2, 0xfd, 0x50, 0xf9, 0x50, 0x07, 0xce, 0x2a, 0xdf, 0xfb, 0x75, 0x70, 0x49, 0x5e, 0x5d, 0xf7, 0x1b, 0x0a, 0x76, 0x1f, 0xe7, 0xe3, 0xc7, 0x0a, 0xc7, 0xee, 0xca, 0x4e, 0xa2, 0xe6, 0xae, 0xe8, 0x1a, 0x2c, 0x3b, 0xa9, 0x12, 0x77, 0xb1, 0x47, 0x3c, 0xb5, 0xab, 0x32, 0x26, 0x18, 0x0d, 0x43, 0x51, 0x6b, 0x11, 0x0c, 0x45, 0xed, 0x52, 0x7d, 0xce, 0xe8, 0x75, 0x6c, 0xe1, 0xda, 0xaf, 0x42, 0x1c, 0xc6, 0x21, 0x23, 0x1f, 0x5d, 0x2d, 0x48, 0xf8, 0x20, 0x67, 0x2f, 0x49, 0x3d, 0x3e, 0x5d, 0xc2, 0x53, 0xc8, 0xe0, 0x3d, 0xe2, 0xdc, 0x51, 0x2f, 0x44, 0xc9, 0x72, 0xb6, 0x04, 0xa0, 0x19, 0x1f, 0x03, 0xb9, 0x0f, 0x57, 0x80, 0x55, 0x41, 0x10, 0x7e, 0x7c, 0x78, 0xdc, 0xbb, 0x82, 0x6e, 0x6a, 0xd9, 0x0e, 0xac, 0x87, 0x0c, 0xfd, 0xc0, 0x79, 0xdf, 0xf5, 0x98, 0xfe, 0x9c, 0x58, 0xa9, 0x63, 0xc2, 0x99, 0x31, 0x09, 0x1c, 0x50, 0xcf, 0x03, 0x4f, 0x96, 0xef, 0x98, 0x56, 0x44, 0xc2, 0x0f, 0x63, 0x20, 0x19, 0x0b, 0x60, 0x28, 0x09, 0xb2, 0x3e, 0xe5, 0xe3, 0x91, 0xc2, 0x98, 0x3d, 0xc0, 0x81, 0x0b, 0x5a, 0xdd, 0x88, 0x6a, 0xc1, 0xff, 0x94, 0x7f, 0xe0, 0x96, 0x6b, 0x67, 0x75, 0x80, 0x53, 0xa1, 0x89, 0x14, 0x19, 0x59, 0xdc, 0x13, 0x67, 0x01, 0x7c, 0x64, 0xfe, 0xeb, 0x7b, 0x8c, 0x97, 0x2d, 0x1a, 0x90, 0x48, 0x4b, 0xea, 0x48, 0xc0, 0x77, 0x23, 0x68, 0x65, 0x19, 0xcf, 0xcf, 0x1c, 0x89, 0x93, 0xe0, 0xd2, 0xfd, 0x81, 0x6a, 0x6e, 0xd8, 0x76, 0xad, 0x65, 0xb5, 0xe0, 0xe1, 0xe2, 0x9c, 0x13, 0x70, 0x0e, 0x79, 0x1c, 0xaa, 0xac, 0x0d, 0x3f, 0x10, 0x4e, 0x47, 0x36, 0xb9, 0x23, 0xd3, 0x6a, 0x50, 0x9a, 0xe2, 0x83, 0x94, 0xf8, 0x1b, 0x41, 0x4c, 0x22, 0x92, 0x58, 0x9f, 0xc8, 0xad, 0x36, 0x51, 0x59, 0xa6, 0xbb, 0x86, 0x4f, 0x9d, 0x3a, 0x9f, 0x1d, 0x0b, 0x2e, 0x7f, 0xf8, 0x83, 0xfd, 0x1c, 0x3b, 0xe1, 0x3d, 0xb2, 0xdc, 0x13, 0x18, 0x71, 0xec, 0x63, 0xf3, 0xfc, 0x41, 0x6f, 0x14, 0xec, 0xcc, 0x7f, 0x28, 0xeb, 0x12, 0xc6, 0x4c, 0xa4, 0x92, 0x7f, 0x7a, 0x65, 0xcf, 0x8f, 0x63, 0x47, 0x3e, 0x4f, 0xeb, 0x03, 0x7b, 0x20, 0xf8, 0x01, 0xa2, 0x9d, 0xe2, 0x5f, 0x85, 0xfb, 0x7b, 0xdf, 0x10, 0x45, 0x2f, 0x6f, 0xb2, 0x6b, 0xff, 0x69, 0xf5, 0x64, 0x8e, 0x18, 0x71, 0x7a, 0x04, 0x31, 0xc3, 0xf8, 0xa0, 0x6c, 0x0f, 0x0a, 0x57, 0x83, 0x83, 0x58, 0xda, 0xaf, 0x99, 0xe6, 0x68, 0x13, 0xe8, 0x15, 0xbc, 0xd7, 0xef, 0xb2, 0x4b, 0x08, 0x18, 0x97, 0xb2, 0x77, 0x0c, 0xb5, 0x96, 0xdb, 0x21, 0x14, 0x39, 0x52, 0x9f, 0x83, 0x47, 0x96, 0xe8, 0x9f, 0x94, 0xe2, 0x73, 0x40, 0x02, 0x7f, 0xbd, 0xb9, 0x65, 0x6a, 0x33, 0x15, 0xb8, 0xc8, 0x9d, 0x12, 0xf9, 0x14, 0x04, 0x77, 0x56, 0xdc, 0x87, 0xd2, 0xca, 0xb2, 0x05, 0x99, 0xad, 0xa6, 0xd2, 0x81, 0x8f, 0x64, 0xcd, 0xe5, 0x70, 0x2c, 0xbf, 0xc0, 0xb6, 0xb7, 0xa8, 0x4a, 0x45, 0x6b, 0x98, 0x8f, 0x5b, 0xb8, 0x87, 0xf5, 0x64, 0xd1, 0x67, 0xd6, 0xdd, 0x76, 0x29, 0xf0, 0x77, 0x45, 0xfc, 0x27, 0xa4, 0x4a, 0xac, 0xaa, 0x1a, 0x90, 0xbe, 0xf8, 0x91, 0x50, 0x30, 0x6d, 0x73, 0x49, 0x3c, 0xab, 0xa4, 0xaf, 0x13, 0xa8, 0xdd, 0x0a, 0xf5, 0xc3, 0x34, 0x98, 0xb4, 0x7f, 0x0b, 0xb4, 0x63, 0x0f, 0xe3, 0x6e, 0xcc, 0xf8, 0x1d, 0xea, 0x34, 0x71, 0x8b, 0x06, 0xa5, 0x4f, 0x81, 0x12, 0xa9, 0xfd, 0xb8, 0x43}},
+	{"-1500566381192798663042470094195709329888702572609999105286667163606153967917290138712408909178830809119008530236180974166477902167438722120032328817587204550920260039698718901932896233377293832747667996098291476468951412311792579258943277768740116090186686963715856483147820131067091322876669577393210366426487028489206389247040659375214497672166049911500383423054774768058254673393263777607084960848658501529675225559011863409579602879830226289200557853195239635009395081629845517655774307827048680743808664945667425540772434721298573889660136104342949269877806888346513652384111162522895043239369803590295673472600852282901495791087130835483730406094888840219829189061112151151001898468218215751327382511813082884657126285166508024920536549363279290734920537316417286759974845704859198588552892947264856714040130408613412473996518038227113385600353365608575770837750435553392852567153310861059766627383200108369176626042676222592985818614861742325706568951932845447397512345181981733524874445871904571909006536844113768514813826258460666950996534336842871477679076553532049073323784011247842133811527684859166963235747571306708361946012941167234981369225227878132777327321706825860067928644566542309248", []byte{0xe2, 0xdb, 0xc3, 0xee, 0xdc, 0xd0, 0xa4, 0xdc, 0x41, 0xec, 0xf7, 0xf3, 0x53, 0x2f, 0xd9, 0x5e, 0xe5, 0xbf, 0x5e, 0xea, 0x84, 0xde, 0x00, 0x79, 0x48, 0xc6, 0xf4, 0xd0, 0x29, 0xd9, 0x41, 0xb3, 0xc1, 0x31, 0xe0, 0x18, 0x42, 0xa5, 0x76, 0x88, 0x95, 0x60, 0xe8, 0x55, 0x51, 0x98, 0x01, 0xdb, 0x58, 0x0f, 0x76, 0xe5, 0x23, 0xb3, 0xa3, 0x8b, 0xb6, 0x8b, 0x66, 0x30, 0xd2, 0xb4, 0x13, 0x44, 0xd7, 0xa1, 0x6f, 0xa1, 0xee, 0x41, 0xab, 0x87, 0x5b, 0x64, 0x53, 0x80, 0x1b, 0x1b, 0x15, 0xba, 0x7e, 0x19, 0xbd, 0xc5, 0x9e, 0xfa, 0x1e, 0x59, 0x19, 0x56, 0x59, 0x7e, 0xa3, 0x2d, 0x97, 0xc8, 0xd9, 0x9f, 0xd3, 0x9b, 0x43, 0x25, 0x31, 0x4b, 0x17, 0x5c, 0x5d, 0x95, 0xd2, 0x5a, 0x91, 0xca, 0x83, 0xe9, 0x16, 0x33, 0x10, 0x26, 0x65, 0x31, 0x79, 0xa3, 0xf7, 0x89, 0xd5, 0xe3, 0x8d, 0x45, 0x86, 0x2a, 0xc9, 0xd8, 0x40, 0x93, 0xd8, 0xbf, 0x6f, 0xfa, 0x13, 0xf5, 0x4a, 0x62, 0x15, 0xd9, 0x55, 0xd9, 0xf6, 0xcc, 0xc2, 0xdb, 0xbc, 0xce, 0x50, 0x7a, 0x45, 0xca, 0xca, 0x54, 0x20, 0x76, 0x8e, 0x26, 0x9a, 0x5d, 0x3b, 0x23, 0xad, 0x80, 0xa5, 0xae, 0x63, 0x27, 0x03, 0x10, 0x65, 0x06, 0x6e, 0x65, 0x38, 0x70, 0x10, 0xef, 0xfb, 0xbc, 0xcf, 0xf3, 0x3d, 0x0a, 0x40, 0xe7, 0xd3, 0x20, 0x5d, 0x4f, 0x84, 0xd8, 0xcb, 0xea, 0x65, 0x28, 0x26, 0x15, 0x54, 0x08, 0x77, 0x07, 0xd4, 0x21, 0xb4, 0x69, 0xc6, 0x70, 0x02, 0xd2, 0x5d, 0x4b, 0x7f, 0xf6, 0xb4, 0x11, 0x7d, 0x1b, 0x74, 0x59, 0x1f, 0x2d, 0x5d, 0x75, 0x5c, 0x1a, 0x6e, 0x78, 0xad, 0x12, 0x8d, 0x3b, 0x52, 0x0d, 0x4a, 0x9f, 0x28, 0x22, 0xc4, 0x36, 0xb3, 0xdf, 0xd5, 0xa3, 0xa3, 0xa7, 0x06, 0xea, 0x49, 0x16, 0x01, 0xc8, 0xb2, 0x27, 0xab, 0x04, 0xa2, 0x62, 0x93, 0xcb, 0xdc, 0xfe, 0x33, 0xe4, 0x31, 0x58, 0x7c, 0x08, 0x23, 0x4c, 0x88, 0x1e, 0x9f, 0xc9, 0x39, 0x46, 0xea, 0x7a, 0x69, 0xfa, 0xff, 0x38, 0x87, 0x6b, 0xde, 0x7c, 0x6b, 0xfa, 0x2f, 0x81, 0xff, 0xb1, 0x82, 0x34, 0x38, 0xb8, 0xd1, 0xbf, 0x68, 0x60, 0x07, 0x3d, 0x91, 0x4e, 0xb2, 0x02, 0x1a, 0x05, 0x70, 0xb7, 0x26, 0xbb, 0x95, 0xad, 0xfd, 0xcc, 0x52, 0x80, 0xf9, 0xda, 0x45, 0x04, 0x24, 0xc4, 0x8f, 0x46, 0x22, 0x9a, 0x0d, 0xa0, 0x88, 0x03, 0x54, 0x2d, 0x2f, 0x54, 0x1b, 0xf1, 0xe5, 0xfe, 0xa0, 0x6c, 0x70, 0x31, 0xb1, 0x36, 0x8b, 0xcf, 0x33, 0xf5, 0xc1, 0x77, 0x6c, 0x89, 0xa3, 0xb3, 0xd9, 0x66, 0x5d, 0xb8, 0x40, 0x66, 0xb3, 0x0d, 0xcd, 0x0c, 0xde, 0xd4, 0x6c, 0x55, 0x66, 0x95, 0x78, 0x7f, 0xc9, 0x0a, 0x8e, 0x41, 0x50, 0xc2, 0xe9, 0x88, 0x91, 0xce, 0x56, 0xa2, 0xc6, 0xc4, 0x87, 0xb0, 0x25, 0xc9, 0x74, 0xf6, 0x58, 0xbe, 0xde, 0xf9, 0xee, 0x37, 0x5c, 0xfe, 0x54, 0xc1, 0x68, 0x40, 0x64, 0x99, 0x66, 0x2e, 0x18, 0x6b, 0xa6, 0x0a, 0xfe, 0x13, 0xec, 0x1e, 0x6f, 0xf3, 0xa0, 0xc9, 0x17, 0x9b, 0x6e, 0x92, 0xf2, 0x42, 0xfb, 0xbd, 0xfb, 0x11, 0x53, 0x7c, 0xeb, 0xd4, 0xd2, 0x16, 0xaf, 0x20, 0x5e, 0x42, 0x09, 0xea, 0x92, 0x0b, 0xab, 0x94, 0xaa, 0xaf, 0x23, 0xda, 0xda, 0xe3, 0x40, 0xc1, 0x5a, 0xab, 0xc2, 0xdd, 0x8d, 0x76, 0x62, 0xb3, 0xd4, 0x13, 0xac, 0x0c, 0x06, 0xa9, 0x98, 0x27, 0xa8, 0x34, 0x94, 0xd6, 0x85, 0x99, 0x24, 0x7e, 0x8a, 0xf1, 0xf8, 0x6d, 0xef, 0x66, 0xf0, 0xe6, 0xc9, 0x2c, 0x4d, 0x1f, 0x3e, 0xfa, 0x28, 0x80}},
+}
+
+func TestVeryBigInts(t *testing.T) {
+	for _, tc := range stringCases {
+		num, ok := new(big.Int).SetString(tc.numStr, 10)
+		assert.True(t, ok)
+
+		result := bytesToInt(tc.buf)
+		assert.Equal(t, num, result, "error while converting %s from bytes", tc.numStr)
+		assert.Equal(t, tc.buf, intToBytes(result), "error while converting %s to bytes", tc.numStr)
+	}
+
+	for _, tc := range stdlibCases {
+		num, ok := new(big.Int).SetString(tc.numStr, 10)
+		assert.True(t, ok)
+
+		result := bytesToInt(util.ArrayReverse(tc.buf))
+		assert.Equal(t, num, result, "error while converting %s from bytes", tc.numStr)
+	}
+}