diff --git a/pkg/compiler/syscall_test.go b/pkg/compiler/syscall_test.go
index d190f7664..ba62874f6 100644
--- a/pkg/compiler/syscall_test.go
+++ b/pkg/compiler/syscall_test.go
@@ -61,10 +61,6 @@ func TestSyscallExecution(t *testing.T) {
 	sigs := "[]interop.Signature{" + sig + "}"
 	sctx := "storage.Context{}"
 	interops := map[string]syscallTestCase{
-		"binary.Base58Decode":                {interopnames.SystemBinaryBase58Decode, []string{b}, false},
-		"binary.Base58Encode":                {interopnames.SystemBinaryBase58Encode, []string{b}, false},
-		"binary.Base64Decode":                {interopnames.SystemBinaryBase64Decode, []string{b}, false},
-		"binary.Base64Encode":                {interopnames.SystemBinaryBase64Encode, []string{b}, false},
 		"binary.Deserialize":                 {interopnames.SystemBinaryDeserialize, []string{b}, false},
 		"binary.Serialize":                   {interopnames.SystemBinarySerialize, []string{"10"}, false},
 		"contract.Call":                      {interopnames.SystemContractCall, []string{u160, `"m"`, "1", "3"}, false},
@@ -203,20 +199,20 @@ func TestNotify(t *testing.T) {
 
 func TestSyscallInGlobalInit(t *testing.T) {
 	src := `package foo
-		import "github.com/nspcc-dev/neo-go/pkg/interop/binary"
-		var a = binary.Base58Decode([]byte("5T"))
-		func Main() []byte {
+		import "github.com/nspcc-dev/neo-go/pkg/interop/runtime"
+		var a = runtime.CheckWitness([]byte("5T"))
+		func Main() bool {
 			return a
 		}`
 	v, s := vmAndCompileInterop(t, src)
-	s.interops[interopnames.ToID([]byte(interopnames.SystemBinaryBase58Decode))] = func(v *vm.VM) error {
+	s.interops[interopnames.ToID([]byte(interopnames.SystemRuntimeCheckWitness))] = func(v *vm.VM) error {
 		s := v.Estack().Pop().Value().([]byte)
 		require.Equal(t, "5T", string(s))
-		v.Estack().PushVal([]byte{1, 2})
+		v.Estack().PushVal(true)
 		return nil
 	}
 	require.NoError(t, v.Run())
-	require.Equal(t, []byte{1, 2}, v.Estack().Pop().Value())
+	require.Equal(t, true, v.Estack().Pop().Value())
 }
 
 func TestOpcode(t *testing.T) {
diff --git a/pkg/core/interop/binary/encode.go b/pkg/core/interop/binary/encode.go
index 0cc294fef..75ab0d515 100644
--- a/pkg/core/interop/binary/encode.go
+++ b/pkg/core/interop/binary/encode.go
@@ -1,9 +1,6 @@
 package binary
 
 import (
-	"encoding/base64"
-
-	"github.com/mr-tron/base58"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
 )
@@ -17,41 +14,3 @@ func Serialize(ic *interop.Context) error {
 func Deserialize(ic *interop.Context) error {
 	return vm.RuntimeDeserialize(ic.VM)
 }
-
-// EncodeBase64 encodes top stack item into a base64 string.
-func EncodeBase64(ic *interop.Context) error {
-	src := ic.VM.Estack().Pop().Bytes()
-	result := base64.StdEncoding.EncodeToString(src)
-	ic.VM.Estack().PushVal([]byte(result))
-	return nil
-}
-
-// DecodeBase64 decodes top stack item from base64 string to byte array.
-func DecodeBase64(ic *interop.Context) error {
-	src := ic.VM.Estack().Pop().String()
-	result, err := base64.StdEncoding.DecodeString(src)
-	if err != nil {
-		return err
-	}
-	ic.VM.Estack().PushVal(result)
-	return nil
-}
-
-// EncodeBase58 encodes top stack item into a base58 string.
-func EncodeBase58(ic *interop.Context) error {
-	src := ic.VM.Estack().Pop().Bytes()
-	result := base58.Encode(src)
-	ic.VM.Estack().PushVal([]byte(result))
-	return nil
-}
-
-// DecodeBase58 decodes top stack item from base58 string to byte array.
-func DecodeBase58(ic *interop.Context) error {
-	src := ic.VM.Estack().Pop().String()
-	result, err := base58.Decode(src)
-	if err != nil {
-		return err
-	}
-	ic.VM.Estack().PushVal(result)
-	return nil
-}
diff --git a/pkg/core/interop/binary/encode_test.go b/pkg/core/interop/binary/encode_test.go
index eeda9f3a2..3318b3588 100644
--- a/pkg/core/interop/binary/encode_test.go
+++ b/pkg/core/interop/binary/encode_test.go
@@ -1,11 +1,9 @@
 package binary
 
 import (
-	"encoding/base64"
 	"math/big"
 	"testing"
 
-	"github.com/mr-tron/base58"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
@@ -49,44 +47,3 @@ func TestRuntimeSerialize(t *testing.T) {
 		})
 	})
 }
-
-func TestRuntimeEncodeDecode(t *testing.T) {
-	original := []byte("my pretty string")
-	encoded64 := base64.StdEncoding.EncodeToString(original)
-	encoded58 := base58.Encode(original)
-	v := vm.New()
-	ic := &interop.Context{VM: v}
-
-	t.Run("Encode64", func(t *testing.T) {
-		v.Estack().PushVal(original)
-		require.NoError(t, EncodeBase64(ic))
-		actual := v.Estack().Pop().Bytes()
-		require.Equal(t, []byte(encoded64), actual)
-	})
-	t.Run("Encode58", func(t *testing.T) {
-		v.Estack().PushVal(original)
-		require.NoError(t, EncodeBase58(ic))
-		actual := v.Estack().Pop().Bytes()
-		require.Equal(t, []byte(encoded58), actual)
-	})
-	t.Run("Decode64/positive", func(t *testing.T) {
-		v.Estack().PushVal(encoded64)
-		require.NoError(t, DecodeBase64(ic))
-		actual := v.Estack().Pop().Bytes()
-		require.Equal(t, original, actual)
-	})
-	t.Run("Decode64/error", func(t *testing.T) {
-		v.Estack().PushVal(encoded64 + "%")
-		require.Error(t, DecodeBase64(ic))
-	})
-	t.Run("Decode58/positive", func(t *testing.T) {
-		v.Estack().PushVal(encoded58)
-		require.NoError(t, DecodeBase58(ic))
-		actual := v.Estack().Pop().Bytes()
-		require.Equal(t, original, actual)
-	})
-	t.Run("Decode58/error", func(t *testing.T) {
-		v.Estack().PushVal(encoded58 + "%")
-		require.Error(t, DecodeBase58(ic))
-	})
-}
diff --git a/pkg/core/interop/interopnames/names.go b/pkg/core/interop/interopnames/names.go
index ab915a976..1858cbacc 100644
--- a/pkg/core/interop/interopnames/names.go
+++ b/pkg/core/interop/interopnames/names.go
@@ -2,10 +2,6 @@ package interopnames
 
 // Names of all used interops.
 const (
-	SystemBinaryBase58Decode                 = "System.Binary.Base58Decode"
-	SystemBinaryBase58Encode                 = "System.Binary.Base58Encode"
-	SystemBinaryBase64Decode                 = "System.Binary.Base64Decode"
-	SystemBinaryBase64Encode                 = "System.Binary.Base64Encode"
 	SystemBinaryDeserialize                  = "System.Binary.Deserialize"
 	SystemBinarySerialize                    = "System.Binary.Serialize"
 	SystemCallbackCreate                     = "System.Callback.Create"
@@ -50,10 +46,6 @@ const (
 )
 
 var names = []string{
-	SystemBinaryBase58Decode,
-	SystemBinaryBase58Encode,
-	SystemBinaryBase64Decode,
-	SystemBinaryBase64Encode,
 	SystemBinaryDeserialize,
 	SystemBinarySerialize,
 	SystemCallbackCreate,
diff --git a/pkg/core/interops.go b/pkg/core/interops.go
index 0952efc7c..58bc3840b 100644
--- a/pkg/core/interops.go
+++ b/pkg/core/interops.go
@@ -31,10 +31,6 @@ func SpawnVM(ic *interop.Context) *vm.VM {
 
 // All lists are sorted, keep 'em this way, please.
 var systemInterops = []interop.Function{
-	{Name: interopnames.SystemBinaryBase58Decode, Func: binary.DecodeBase58, Price: 1 << 12, ParamCount: 1},
-	{Name: interopnames.SystemBinaryBase58Encode, Func: binary.EncodeBase58, Price: 1 << 12, ParamCount: 1},
-	{Name: interopnames.SystemBinaryBase64Decode, Func: binary.DecodeBase64, Price: 1 << 12, ParamCount: 1},
-	{Name: interopnames.SystemBinaryBase64Encode, Func: binary.EncodeBase64, Price: 1 << 12, ParamCount: 1},
 	{Name: interopnames.SystemBinaryDeserialize, Func: binary.Deserialize, Price: 1 << 14, ParamCount: 1},
 	{Name: interopnames.SystemBinarySerialize, Func: binary.Serialize, Price: 1 << 12, ParamCount: 1},
 	{Name: interopnames.SystemContractCall, Func: contract.Call, Price: 1 << 15,
diff --git a/pkg/core/native/std_test.go b/pkg/core/native/std_test.go
index afbe7460f..ea89b9530 100644
--- a/pkg/core/native/std_test.go
+++ b/pkg/core/native/std_test.go
@@ -1,10 +1,12 @@
 package native
 
 import (
+	"encoding/base64"
 	"math"
 	"math/big"
 	"testing"
 
+	"github.com/mr-tron/base58"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
@@ -138,3 +140,53 @@ func TestStdLibJSON(t *testing.T) {
 		})
 	})
 }
+
+func TestStdLibEncodeDecode(t *testing.T) {
+	s := newStd()
+	original := []byte("my pretty string")
+	encoded64 := base64.StdEncoding.EncodeToString(original)
+	encoded58 := base58.Encode(original)
+	ic := &interop.Context{VM: vm.New()}
+	var actual stackitem.Item
+
+	t.Run("Encode64", func(t *testing.T) {
+		require.NotPanics(t, func() {
+			actual = s.base64Encode(ic, []stackitem.Item{stackitem.Make(original)})
+		})
+		require.Equal(t, stackitem.Make(encoded64), actual)
+	})
+	t.Run("Encode58", func(t *testing.T) {
+		require.NotPanics(t, func() {
+			actual = s.base58Encode(ic, []stackitem.Item{stackitem.Make(original)})
+		})
+		require.Equal(t, stackitem.Make(encoded58), actual)
+	})
+	t.Run("Decode64/positive", func(t *testing.T) {
+		require.NotPanics(t, func() {
+			actual = s.base64Decode(ic, []stackitem.Item{stackitem.Make(encoded64)})
+		})
+		require.Equal(t, stackitem.Make(original), actual)
+	})
+	t.Run("Decode64/error", func(t *testing.T) {
+		require.Panics(t, func() {
+			_ = s.base64Decode(ic, []stackitem.Item{stackitem.Make(encoded64 + "%")})
+		})
+		require.Panics(t, func() {
+			_ = s.base64Decode(ic, []stackitem.Item{stackitem.NewInterop(nil)})
+		})
+	})
+	t.Run("Decode58/positive", func(t *testing.T) {
+		require.NotPanics(t, func() {
+			actual = s.base58Decode(ic, []stackitem.Item{stackitem.Make(encoded58)})
+		})
+		require.Equal(t, stackitem.Make(original), actual)
+	})
+	t.Run("Decode58/error", func(t *testing.T) {
+		require.Panics(t, func() {
+			_ = s.base58Decode(ic, []stackitem.Item{stackitem.Make(encoded58 + "%")})
+		})
+		require.Panics(t, func() {
+			_ = s.base58Decode(ic, []stackitem.Item{stackitem.NewInterop(nil)})
+		})
+	})
+}
diff --git a/pkg/interop/binary/binary.go b/pkg/interop/binary/binary.go
index 9d25a589e..a96f5f527 100644
--- a/pkg/interop/binary/binary.go
+++ b/pkg/interop/binary/binary.go
@@ -20,27 +20,3 @@ func Serialize(item interface{}) []byte {
 func Deserialize(b []byte) interface{} {
 	return neogointernal.Syscall1("System.Binary.Deserialize", b)
 }
-
-// Base64Encode encodes given byte slice into a base64 string and returns byte
-// representation of this string. It uses `System.Binary.Base64Encode` interop.
-func Base64Encode(b []byte) string {
-	return neogointernal.Syscall1("System.Binary.Base64Encode", b).(string)
-}
-
-// Base64Decode decodes given base64 string represented as a byte slice into
-// byte slice. It uses `System.Binary.Base64Decode` interop.
-func Base64Decode(b []byte) []byte {
-	return neogointernal.Syscall1("System.Binary.Base64Decode", b).([]byte)
-}
-
-// Base58Encode encodes given byte slice into a base58 string and returns byte
-// representation of this string. It uses `System.Binary.Base58Encode` syscall.
-func Base58Encode(b []byte) string {
-	return neogointernal.Syscall1("System.Binary.Base58Encode", b).(string)
-}
-
-// Base58Decode decodes given base58 string represented as a byte slice into
-// a new byte slice. It uses `System.Binary.Base58Decode` syscall.
-func Base58Decode(b []byte) []byte {
-	return neogointernal.Syscall1("System.Binary.Base58Decode", b).([]byte)
-}