diff --git a/pkg/compiler/interop_test.go b/pkg/compiler/interop_test.go
index 360c81f3a..2ba7a5f2f 100644
--- a/pkg/compiler/interop_test.go
+++ b/pkg/compiler/interop_test.go
@@ -45,7 +45,7 @@ func TestTypeConstantSize(t *testing.T) {
 
 	t.Run("Hash160", func(t *testing.T) {
 		t.Run("good", func(t *testing.T) {
-			a := make(cinterop.Hash160, 20)
+			a := make(cinterop.Hash160, smartcontract.Hash160Len)
 			src := fmt.Sprintf(src, a, a)
 			eval(t, src, []byte(a))
 		})
@@ -58,7 +58,7 @@ func TestTypeConstantSize(t *testing.T) {
 	})
 	t.Run("Hash256", func(t *testing.T) {
 		t.Run("good", func(t *testing.T) {
-			a := make(cinterop.Hash256, 32)
+			a := make(cinterop.Hash256, smartcontract.Hash256Len)
 			src := fmt.Sprintf(src, a, a)
 			eval(t, src, []byte(a))
 		})
diff --git a/pkg/compiler/syscall_test.go b/pkg/compiler/syscall_test.go
index 22cbb2756..d42610d07 100644
--- a/pkg/compiler/syscall_test.go
+++ b/pkg/compiler/syscall_test.go
@@ -15,6 +15,7 @@ import (
 	istorage "github.com/nspcc-dev/neo-go/pkg/core/interop/storage"
 	"github.com/nspcc-dev/neo-go/pkg/interop/contract"
 	"github.com/nspcc-dev/neo-go/pkg/interop/storage"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
@@ -488,6 +489,6 @@ func TestInteropTypesComparison(t *testing.T) {
 	}
 	typeCheck(t, "Hash160", util.Uint160Size)
 	typeCheck(t, "Hash256", util.Uint256Size)
-	typeCheck(t, "Signature", 64)
-	typeCheck(t, "PublicKey", 33)
+	typeCheck(t, "Signature", smartcontract.SignatureLen)
+	typeCheck(t, "PublicKey", smartcontract.PublicKeyLen)
 }
diff --git a/pkg/consensus/payload_test.go b/pkg/consensus/payload_test.go
index 3101f6072..1eddab699 100644
--- a/pkg/consensus/payload_test.go
+++ b/pkg/consensus/payload_test.go
@@ -228,13 +228,13 @@ func randomRecoveryMessage(t *testing.T) *recoveryMessage {
 			{
 				ViewNumber:       0,
 				ValidatorIndex:   1,
-				Signature:        [64]byte{1, 2, 3},
+				Signature:        [keys.SignatureLen]byte{1, 2, 3},
 				InvocationScript: random.Bytes(20),
 			},
 			{
 				ViewNumber:       0,
 				ValidatorIndex:   2,
-				Signature:        [64]byte{11, 3, 4, 98},
+				Signature:        [keys.SignatureLen]byte{11, 3, 4, 98},
 				InvocationScript: random.Bytes(10),
 			},
 		},
diff --git a/pkg/core/blockchain_neotest_test.go b/pkg/core/blockchain_neotest_test.go
index ffe9f23ba..043939c5a 100644
--- a/pkg/core/blockchain_neotest_test.go
+++ b/pkg/core/blockchain_neotest_test.go
@@ -559,9 +559,9 @@ func TestBlockchain_VerifyHashAgainstScript(t *testing.T) {
 		require.True(t, errors.Is(err, core.ErrVerificationFailed))
 	})
 	t.Run("BadResult", func(t *testing.T) {
-		verif := make([]byte, 66)
+		verif := make([]byte, keys.SignatureLen+2)
 		verif[0] = byte(opcode.PUSHDATA1)
-		verif[1] = 64
+		verif[1] = keys.SignatureLen
 		w := &transaction.Witness{
 			InvocationScript:   []byte{byte(opcode.NOP)},
 			VerificationScript: verif,
@@ -1634,7 +1634,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 						VerificationScript: rawScript,
 					},
 					{
-						InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
+						InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
 					},
 				}
 				return tx
@@ -1679,7 +1679,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 							VerificationScript: committee.Script(),
 						},
 						{
-							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
+							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
 						},
 					}
 					require.Error(t, bc.VerifyTx(tx))
@@ -1698,7 +1698,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 					}
 					tx.Scripts = []transaction.Witness{
 						{
-							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
+							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
 						},
 						{
 							InvocationScript:   committee.SignHashable(uint32(netmode.UnitTestNet), tx),
@@ -1725,7 +1725,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 							VerificationScript: committee.Script(),
 						},
 						{
-							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
+							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
 						},
 					}
 					require.Error(t, bc.VerifyTx(tx))
@@ -1766,7 +1766,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 							VerificationScript: committee.Script(),
 						},
 						{
-							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, acc.SignHashable(uint32(netmode.UnitTestNet), tx)...),
+							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, acc.SignHashable(uint32(netmode.UnitTestNet), tx)...),
 						},
 					}
 					require.Error(t, bc.VerifyTx(tx))
@@ -1781,7 +1781,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 					}
 					tx.Scripts = []transaction.Witness{
 						{
-							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
+							InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, notary.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), tx)...),
 						},
 					}
 					require.Error(t, bc.VerifyTx(tx))
@@ -1831,7 +1831,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 				nativeprices.NotaryVerificationPrice*bc.GetBaseExecFee() // Notary witness verification price
 			tx.Scripts = []transaction.Witness{
 				{
-					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...),
+					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...),
 					VerificationScript: []byte{},
 				},
 				{
@@ -1858,7 +1858,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 			tx.NetworkFee-- // to check that NetworkFee was set correctly in getPartiallyFilledTx
 			tx.Scripts = []transaction.Witness{
 				{
-					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...),
+					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...),
 					VerificationScript: []byte{},
 				},
 				{
diff --git a/pkg/core/interop/runtime/engine.go b/pkg/core/interop/runtime/engine.go
index 73654db19..daadcda5a 100644
--- a/pkg/core/interop/runtime/engine.go
+++ b/pkg/core/interop/runtime/engine.go
@@ -73,9 +73,20 @@ func Notify(ic *interop.Context) error {
 	if len(name) > MaxEventNameLen {
 		return fmt.Errorf("event name must be less than %d", MaxEventNameLen)
 	}
-	if !ic.VM.Context().IsDeployed() {
+	curHash := ic.VM.GetCurrentScriptHash()
+	ctr, err := ic.GetContract(curHash)
+	if err != nil {
 		return errors.New("notifications are not allowed in dynamic scripts")
 	}
+	ev := ctr.Manifest.ABI.GetEvent(name)
+	if ev == nil {
+		ic.Log.Info("bad notification", zap.String("contract", curHash.StringLE()), zap.String("event", name), zap.Error(fmt.Errorf("event %s does not exist", name)))
+	} else {
+		err = ev.CheckCompliance(args)
+		if err != nil {
+			ic.Log.Info("bad notification", zap.String("contract", curHash.StringLE()), zap.String("event", name), zap.Error(err))
+		}
+	}
 
 	// But it has to be serializable, otherwise we either have some broken
 	// (recursive) structure inside or an interop item that can't be used
@@ -87,7 +98,7 @@ func Notify(ic *interop.Context) error {
 	if len(bytes) > MaxNotificationSize {
 		return fmt.Errorf("notification size shouldn't exceed %d", MaxNotificationSize)
 	}
-	ic.AddNotification(ic.VM.GetCurrentScriptHash(), name, stackitem.DeepCopy(stackitem.NewArray(args), true).(*stackitem.Array))
+	ic.AddNotification(curHash, name, stackitem.DeepCopy(stackitem.NewArray(args), true).(*stackitem.Array))
 	return nil
 }
 
diff --git a/pkg/core/interop/runtime/engine_test.go b/pkg/core/interop/runtime/engine_test.go
index 4ddf628ae..656a78dcb 100644
--- a/pkg/core/interop/runtime/engine_test.go
+++ b/pkg/core/interop/runtime/engine_test.go
@@ -8,11 +8,9 @@ import (
 
 	"github.com/nspcc-dev/neo-go/internal/random"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
-	"github.com/nspcc-dev/neo-go/pkg/core/dao"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
-	"github.com/nspcc-dev/neo-go/pkg/smartcontract/nef"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
@@ -131,55 +129,3 @@ func TestLog(t *testing.T) {
 		require.Equal(t, h.StringLE(), logMsg["script"])
 	})
 }
-
-func TestNotify(t *testing.T) {
-	h := random.Uint160()
-	caller := random.Uint160()
-	exe, err := nef.NewFile([]byte{1})
-	require.NoError(t, err)
-	newIC := func(name string, args interface{}) *interop.Context {
-		ic := &interop.Context{VM: vm.New(), DAO: &dao.Simple{}}
-		ic.VM.LoadNEFMethod(exe, caller, h, callflag.NoneFlag, true, 0, -1, nil)
-		ic.VM.Estack().PushVal(args)
-		ic.VM.Estack().PushVal(name)
-		return ic
-	}
-	t.Run("big name", func(t *testing.T) {
-		ic := newIC(string(make([]byte, MaxEventNameLen+1)), stackitem.NewArray([]stackitem.Item{stackitem.Null{}}))
-		require.Error(t, Notify(ic))
-	})
-	t.Run("dynamic script", func(t *testing.T) {
-		ic := &interop.Context{VM: vm.New(), DAO: &dao.Simple{}}
-		ic.VM.LoadScriptWithHash([]byte{1}, h, callflag.NoneFlag)
-		ic.VM.Estack().PushVal(stackitem.NewArray([]stackitem.Item{stackitem.Make(42)}))
-		ic.VM.Estack().PushVal("event")
-		require.Error(t, Notify(ic))
-	})
-	t.Run("recursive struct", func(t *testing.T) {
-		arr := stackitem.NewArray([]stackitem.Item{stackitem.Null{}})
-		arr.Append(arr)
-		ic := newIC("event", arr)
-		require.Error(t, Notify(ic))
-	})
-	t.Run("big notification", func(t *testing.T) {
-		bs := stackitem.NewByteArray(make([]byte, MaxNotificationSize+1))
-		arr := stackitem.NewArray([]stackitem.Item{bs})
-		ic := newIC("event", arr)
-		require.Error(t, Notify(ic))
-	})
-	t.Run("good", func(t *testing.T) {
-		arr := stackitem.NewArray([]stackitem.Item{stackitem.Make(42)})
-		ic := newIC("good event", arr)
-		require.NoError(t, Notify(ic))
-		require.Equal(t, 1, len(ic.Notifications))
-
-		arr.MarkAsReadOnly() // tiny hack for test to be able to compare object references.
-		ev := ic.Notifications[0]
-		require.Equal(t, "good event", ev.Name)
-		require.Equal(t, h, ev.ScriptHash)
-		require.Equal(t, arr, ev.Item)
-		// Check deep copy.
-		arr.Value().([]stackitem.Item)[0] = stackitem.Null{}
-		require.NotEqual(t, arr, ev.Item)
-	})
-}
diff --git a/pkg/core/interop/runtime/ext_test.go b/pkg/core/interop/runtime/ext_test.go
index 43e5fff56..d5a878036 100644
--- a/pkg/core/interop/runtime/ext_test.go
+++ b/pkg/core/interop/runtime/ext_test.go
@@ -79,7 +79,7 @@ func loadScriptWithHashAndFlags(ic *interop.Context, script []byte, hash util.Ui
 	ic.VM.GasLimit = -1
 }
 
-func TestBurnGas(t *testing.T) {
+func getDeployedInternal(t *testing.T) (*neotest.Executor, neotest.Signer, *core.Blockchain, *state.Contract) {
 	bc, acc := chain.NewSingle(t)
 	e := neotest.NewExecutor(t, bc, acc, acc)
 	managementInvoker := e.ValidatorInvoker(e.NativeHash(t, nativenames.Management))
@@ -92,6 +92,12 @@ func TestBurnGas(t *testing.T) {
 	tx := managementInvoker.PrepareInvoke(t, "deploy", rawNef, rawManifest)
 	e.AddNewBlock(t, tx)
 	e.CheckHalt(t, tx.Hash())
+
+	return e, acc, bc, cs
+}
+
+func TestBurnGas(t *testing.T) {
+	e, acc, _, cs := getDeployedInternal(t)
 	cInvoker := e.ValidatorInvoker(cs.Hash)
 
 	t.Run("good", func(t *testing.T) {
@@ -539,3 +545,53 @@ func TestGetRandomCompatibility(t *testing.T) {
 	require.NoError(t, runtime.GetRandom(ic))
 	require.Equal(t, "247152297361212656635216876565962360375", ic.VM.Estack().Pop().BigInt().String())
 }
+
+func TestNotify(t *testing.T) {
+	caller := random.Uint160()
+	newIC := func(name string, args interface{}) *interop.Context {
+		_, _, bc, cs := getDeployedInternal(t)
+		ic := bc.GetTestVM(trigger.Application, nil, nil)
+		ic.VM.LoadNEFMethod(&cs.NEF, caller, cs.Hash, callflag.NoneFlag, true, 0, -1, nil)
+		ic.VM.Estack().PushVal(args)
+		ic.VM.Estack().PushVal(name)
+		return ic
+	}
+	t.Run("big name", func(t *testing.T) {
+		ic := newIC(string(make([]byte, runtime.MaxEventNameLen+1)), stackitem.NewArray([]stackitem.Item{stackitem.Null{}}))
+		require.Error(t, runtime.Notify(ic))
+	})
+	t.Run("dynamic script", func(t *testing.T) {
+		ic := newIC("some", stackitem.Null{})
+		ic.VM.LoadScriptWithHash([]byte{1}, random.Uint160(), callflag.NoneFlag)
+		ic.VM.Estack().PushVal(stackitem.NewArray([]stackitem.Item{stackitem.Make(42)}))
+		ic.VM.Estack().PushVal("event")
+		require.Error(t, runtime.Notify(ic))
+	})
+	t.Run("recursive struct", func(t *testing.T) {
+		arr := stackitem.NewArray([]stackitem.Item{stackitem.Null{}})
+		arr.Append(arr)
+		ic := newIC("event", arr)
+		require.Error(t, runtime.Notify(ic))
+	})
+	t.Run("big notification", func(t *testing.T) {
+		bs := stackitem.NewByteArray(make([]byte, runtime.MaxNotificationSize+1))
+		arr := stackitem.NewArray([]stackitem.Item{bs})
+		ic := newIC("event", arr)
+		require.Error(t, runtime.Notify(ic))
+	})
+	t.Run("good", func(t *testing.T) {
+		arr := stackitem.NewArray([]stackitem.Item{stackitem.Make(42)})
+		ic := newIC("good event", arr)
+		require.NoError(t, runtime.Notify(ic))
+		require.Equal(t, 1, len(ic.Notifications))
+
+		arr.MarkAsReadOnly() // tiny hack for test to be able to compare object references.
+		ev := ic.Notifications[0]
+		require.Equal(t, "good event", ev.Name)
+		require.Equal(t, ic.VM.GetCurrentScriptHash(), ev.ScriptHash)
+		require.Equal(t, arr, ev.Item)
+		// Check deep copy.
+		arr.Value().([]stackitem.Item)[0] = stackitem.Null{}
+		require.NotEqual(t, arr, ev.Item)
+	})
+}
diff --git a/pkg/core/native/native_test/gas_test.go b/pkg/core/native/native_test/gas_test.go
index a478b13a9..dd270ade2 100644
--- a/pkg/core/native/native_test/gas_test.go
+++ b/pkg/core/native/native_test/gas_test.go
@@ -120,7 +120,7 @@ func TestGAS_RewardWithP2PSigExtensionsEnabled(t *testing.T) {
 	}
 	tx.Scripts = []transaction.Witness{
 		{
-			InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, notaryNodes[0].SignHashable(uint32(e.Chain.GetConfig().Magic), tx)...),
+			InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, notaryNodes[0].SignHashable(uint32(e.Chain.GetConfig().Magic), tx)...),
 		},
 		{
 			InvocationScript:   e.Committee.SignHashable(uint32(e.Chain.GetConfig().Magic), tx),
diff --git a/pkg/core/native/native_test/management_test.go b/pkg/core/native/native_test/management_test.go
index dd64aeed5..37699f59d 100644
--- a/pkg/core/native/native_test/management_test.go
+++ b/pkg/core/native/native_test/management_test.go
@@ -126,7 +126,7 @@ func TestManagement_ContractDeploy(t *testing.T) {
 		require.NoError(t, err)
 
 		badManifest := cs1.Manifest
-		badManifest.Groups = []manifest.Group{{PublicKey: pkey.PublicKey(), Signature: make([]byte, 64)}}
+		badManifest.Groups = []manifest.Group{{PublicKey: pkey.PublicKey(), Signature: make([]byte, keys.SignatureLen)}}
 		manifB, err := json.Marshal(&badManifest)
 		require.NoError(t, err)
 
@@ -432,7 +432,7 @@ func TestManagement_ContractUpdate(t *testing.T) {
 		require.NoError(t, err)
 
 		var badManifest = cs1.Manifest
-		badManifest.Groups = []manifest.Group{{PublicKey: pkey.PublicKey(), Signature: make([]byte, 64)}}
+		badManifest.Groups = []manifest.Group{{PublicKey: pkey.PublicKey(), Signature: make([]byte, keys.SignatureLen)}}
 		manifB, err := json.Marshal(badManifest)
 		require.NoError(t, err)
 
diff --git a/pkg/core/native/native_test/notary_test.go b/pkg/core/native/native_test/notary_test.go
index 40339ebe5..a7f020f61 100644
--- a/pkg/core/native/native_test/notary_test.go
+++ b/pkg/core/native/native_test/notary_test.go
@@ -221,7 +221,7 @@ func TestNotary_NotaryNodesReward(t *testing.T) {
 		}
 		tx.Scripts = []transaction.Witness{
 			{
-				InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, notaryNodes[0].SignHashable(uint32(e.Chain.GetConfig().Magic), tx)...),
+				InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, notaryNodes[0].SignHashable(uint32(e.Chain.GetConfig().Magic), tx)...),
 			},
 			{
 				InvocationScript:   e.Committee.SignHashable(uint32(e.Chain.GetConfig().Magic), tx),
diff --git a/pkg/crypto/hash/hash.go b/pkg/crypto/hash/hash.go
index 9df09c66f..a997a3514 100644
--- a/pkg/crypto/hash/hash.go
+++ b/pkg/crypto/hash/hash.go
@@ -17,7 +17,7 @@ type Hashable interface {
 }
 
 func getSignedData(net uint32, hh Hashable) []byte {
-	var b = make([]byte, 4+32)
+	var b = make([]byte, 4+util.Uint256Size)
 	binary.LittleEndian.PutUint32(b, net)
 	h := hh.Hash()
 	copy(b[4:], h[:])
diff --git a/pkg/neotest/signer.go b/pkg/neotest/signer.go
index df529e607..333144434 100644
--- a/pkg/neotest/signer.go
+++ b/pkg/neotest/signer.go
@@ -9,6 +9,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
@@ -73,7 +74,7 @@ func (s *signer) ScriptHash() util.Uint160 {
 
 // SignHashable implements Signer interface.
 func (s *signer) SignHashable(magic uint32, item hash.Hashable) []byte {
-	return append([]byte{byte(opcode.PUSHDATA1), 64},
+	return append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen},
 		(*wallet.Account)(s).SignHashable(netmode.Magic(magic), item)...)
 }
 
@@ -131,7 +132,7 @@ func (m multiSigner) SignHashable(magic uint32, item hash.Hashable) []byte {
 	var script []byte
 	for i := 0; i < m.m; i++ {
 		sign := m.accounts[i].SignHashable(netmode.Magic(magic), item)
-		script = append(script, byte(opcode.PUSHDATA1), 64)
+		script = append(script, byte(opcode.PUSHDATA1), keys.SignatureLen)
 		script = append(script, sign...)
 	}
 	return script
diff --git a/pkg/network/payload/notary_request.go b/pkg/network/payload/notary_request.go
index 8c68efe8a..afc8f813b 100644
--- a/pkg/network/payload/notary_request.go
+++ b/pkg/network/payload/notary_request.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
@@ -110,7 +111,7 @@ func (r *P2PNotaryRequest) isValid() error {
 	}
 	if len(r.FallbackTransaction.Scripts[0].InvocationScript) != 66 ||
 		len(r.FallbackTransaction.Scripts[0].VerificationScript) != 0 ||
-		!bytes.HasPrefix(r.FallbackTransaction.Scripts[0].InvocationScript, []byte{byte(opcode.PUSHDATA1), 64}) {
+		!bytes.HasPrefix(r.FallbackTransaction.Scripts[0].InvocationScript, []byte{byte(opcode.PUSHDATA1), keys.SignatureLen}) {
 		return errors.New("fallback transaction has invalid dummy Notary witness")
 	}
 	if !r.FallbackTransaction.HasAttribute(transaction.NotValidBeforeT) {
diff --git a/pkg/network/payload/notary_request_test.go b/pkg/network/payload/notary_request_test.go
index 8e0bc6ea0..41eb073f8 100644
--- a/pkg/network/payload/notary_request_test.go
+++ b/pkg/network/payload/notary_request_test.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/nspcc-dev/neo-go/internal/random"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm/opcode"
 	"github.com/stretchr/testify/require"
@@ -45,21 +46,21 @@ func TestNotaryRequestIsValid(t *testing.T) {
 			MainTransaction: mainTx,
 			FallbackTransaction: &transaction.Transaction{
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 65}, make([]byte, 64)...)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 65}, make([]byte, keys.SignatureLen)...)}, {}},
 			},
 		},
 		"fallback tx: invalid dummy Notary witness (non-empty verification script))": {
 			MainTransaction: mainTx,
 			FallbackTransaction: &transaction.Transaction{
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 1)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 1)}, {}},
 			},
 		},
 		"fallback tx: missing NotValidBefore attribute": {
 			MainTransaction: mainTx,
 			FallbackTransaction: &transaction.Transaction{
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: invalid number of Conflicts attributes": {
@@ -67,7 +68,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 			FallbackTransaction: &transaction.Transaction{
 				Attributes: []transaction.Attribute{{Type: transaction.NotValidBeforeT, Value: &transaction.NotValidBefore{Height: 123}}},
 				Signers:    []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts:    []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts:    []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: does not conflicts with main tx": {
@@ -78,7 +79,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.ConflictsT, Value: &transaction.Conflicts{Hash: util.Uint256{}}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: missing NotaryAssisted attribute": {
@@ -89,7 +90,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.ConflictsT, Value: &transaction.Conflicts{Hash: mainTx.Hash()}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: non-zero NKeys": {
@@ -101,7 +102,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 1}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 		"fallback tx: ValidUntilBlock mismatch": {
@@ -114,7 +115,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 0}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		},
 	}
@@ -134,7 +135,7 @@ func TestNotaryRequestIsValid(t *testing.T) {
 					{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 0}},
 				},
 				Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {}},
+				Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {}},
 			},
 		}
 		require.NoError(t, p.isValid())
@@ -164,7 +165,7 @@ func TestNotaryRequestBytesFromBytes(t *testing.T) {
 		},
 		Signers: []transaction.Signer{{Account: util.Uint160{1, 4, 7}}, {Account: util.Uint160{9, 8, 7}}},
 		Scripts: []transaction.Witness{
-			{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)},
+			{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)},
 			{InvocationScript: []byte{1, 2, 3}, VerificationScript: []byte{1, 2, 3}}},
 	}
 	_ = fallbackTx.Hash()
diff --git a/pkg/network/server_test.go b/pkg/network/server_test.go
index 750878e9f..578e82f7e 100644
--- a/pkg/network/server_test.go
+++ b/pkg/network/server_test.go
@@ -19,6 +19,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/mpt"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/network/capability"
 	"github.com/nspcc-dev/neo-go/pkg/network/payload"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -545,7 +546,7 @@ func TestGetData(t *testing.T) {
 				{Type: transaction.NotaryAssistedT, Value: &transaction.NotaryAssisted{NKeys: 0}},
 			},
 			Signers: []transaction.Signer{{Account: random.Uint160()}, {Account: random.Uint160()}},
-			Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)}, {InvocationScript: []byte{}, VerificationScript: []byte{}}},
+			Scripts: []transaction.Witness{{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)}, {InvocationScript: []byte{}, VerificationScript: []byte{}}},
 		}
 		fallbackTx.Size()
 		fallbackTx.Hash()
diff --git a/pkg/rpcclient/notary/actor.go b/pkg/rpcclient/notary/actor.go
index 06c9ef958..c99a4e7af 100644
--- a/pkg/rpcclient/notary/actor.go
+++ b/pkg/rpcclient/notary/actor.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/neorpc/result"
 	"github.com/nspcc-dev/neo-go/pkg/network/payload"
 	"github.com/nspcc-dev/neo-go/pkg/rpcclient/actor"
@@ -278,7 +279,7 @@ func (a *Actor) SendRequest(mainTx *transaction.Transaction, fbTx *transaction.T
 	if err != nil {
 		return mainHash, fbHash, vub, err
 	}
-	fbTx.Scripts[0].InvocationScript = append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...) // Must be present.
+	fbTx.Scripts[0].InvocationScript = append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...) // Must be present.
 	return a.SendRequestExactly(mainTx, fbTx)
 }
 
@@ -300,7 +301,7 @@ func (a *Actor) SendRequestExactly(mainTx *transaction.Transaction, fbTx *transa
 		FallbackTransaction: fbTx,
 	}
 	req.Witness = transaction.Witness{
-		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, a.sender.SignHashable(a.GetNetwork(), req)...),
+		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, a.sender.SignHashable(a.GetNetwork(), req)...),
 		VerificationScript: a.sender.GetVerificationScript(),
 	}
 	actualHash, err := a.rpc.SubmitP2PNotaryRequest(req)
diff --git a/pkg/rpcclient/rpc.go b/pkg/rpcclient/rpc.go
index 9e2c86264..112689bea 100644
--- a/pkg/rpcclient/rpc.go
+++ b/pkg/rpcclient/rpc.go
@@ -893,7 +893,7 @@ func (c *Client) SignAndPushP2PNotaryRequest(mainTx *transaction.Transaction, fa
 
 	fallbackTx.Scripts = []transaction.Witness{
 		{
-			InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...),
+			InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...),
 			VerificationScript: []byte{},
 		},
 		{
@@ -919,7 +919,7 @@ func (c *Client) SignAndPushP2PNotaryRequest(mainTx *transaction.Transaction, fa
 		FallbackTransaction: fallbackTx,
 	}
 	req.Witness = transaction.Witness{
-		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, acc.SignHashable(m, req)...),
+		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, acc.SignHashable(m, req)...),
 		VerificationScript: acc.GetVerificationScript(),
 	}
 	actualHash, err := c.SubmitP2PNotaryRequest(req)
diff --git a/pkg/services/notary/core_test.go b/pkg/services/notary/core_test.go
index 844aeab92..fe1c9e156 100644
--- a/pkg/services/notary/core_test.go
+++ b/pkg/services/notary/core_test.go
@@ -199,7 +199,7 @@ func TestNotary(t *testing.T) {
 		}
 		fallback.Scripts = []transaction.Witness{
 			{
-				InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...),
+				InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...),
 				VerificationScript: []byte{},
 			},
 		}
@@ -261,7 +261,7 @@ func TestNotary(t *testing.T) {
 				for j := range main.Scripts {
 					main.Scripts[j].VerificationScript = verificationScripts[j]
 					if i == j {
-						main.Scripts[j].InvocationScript = append([]byte{byte(opcode.PUSHDATA1), 64}, acc.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), main)...)
+						main.Scripts[j].InvocationScript = append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, acc.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), main)...)
 					}
 				}
 				main.Scripts = append(main.Scripts, transaction.Witness{}) // empty Notary witness
@@ -310,7 +310,7 @@ func TestNotary(t *testing.T) {
 				require.NoError(t, err)
 			}
 			require.Equal(t, transaction.Witness{
-				InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, acc1.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), requests[0].MainTransaction)...),
+				InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, acc1.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), requests[0].MainTransaction)...),
 				VerificationScript: []byte{},
 			}, completedTx.Scripts[len(completedTx.Scripts)-1])
 		} else {
@@ -325,7 +325,7 @@ func TestNotary(t *testing.T) {
 				require.Equal(t, 2, len(completedTx.Signers))
 				require.Equal(t, 2, len(completedTx.Scripts))
 				require.Equal(t, transaction.Witness{
-					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, acc1.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), req.FallbackTransaction)...),
+					InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, acc1.PrivateKey().SignHashable(uint32(netmode.UnitTestNet), req.FallbackTransaction)...),
 					VerificationScript: []byte{},
 				}, completedTx.Scripts[0])
 
diff --git a/pkg/services/notary/notary.go b/pkg/services/notary/notary.go
index c626fb854..dc3d93a85 100644
--- a/pkg/services/notary/notary.go
+++ b/pkg/services/notary/notary.go
@@ -392,7 +392,7 @@ func (n *Notary) PostPersist() {
 // finalize adds missing Notary witnesses to the transaction (main or fallback) and pushes it to the network.
 func (n *Notary) finalize(acc *wallet.Account, tx *transaction.Transaction, h util.Uint256) error {
 	notaryWitness := transaction.Witness{
-		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, acc.SignHashable(n.Network, tx)...),
+		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, acc.SignHashable(n.Network, tx)...),
 		VerificationScript: []byte{},
 	}
 	for i, signer := range tx.Signers {
@@ -515,7 +515,7 @@ func (n *Notary) verifyIncompleteWitnesses(tx *transaction.Transaction, nKeysExp
 		}
 		// Each verification script is allowed to have either one signature or zero signatures. If signature is provided, then need to verify it.
 		if len(w.InvocationScript) != 0 {
-			if len(w.InvocationScript) != 66 || !bytes.HasPrefix(w.InvocationScript, []byte{byte(opcode.PUSHDATA1), 64}) {
+			if len(w.InvocationScript) != 66 || !bytes.HasPrefix(w.InvocationScript, []byte{byte(opcode.PUSHDATA1), keys.SignatureLen}) {
 				return nil, fmt.Errorf("witness #%d: invocation script should have length = 66 and be of the form [PUSHDATA1, 64, signatureBytes...]", i)
 			}
 		}
diff --git a/pkg/services/notary/notary_test.go b/pkg/services/notary/notary_test.go
index d8375e0d7..d3d173e99 100644
--- a/pkg/services/notary/notary_test.go
+++ b/pkg/services/notary/notary_test.go
@@ -51,7 +51,7 @@ func TestVerifyIncompleteRequest(t *testing.T) {
 	notaryContractHash := util.Uint160{1, 2, 3}
 	bc.NotaryContractScriptHash = notaryContractHash
 	_, ntr, _ := getTestNotary(t, bc, "./testdata/notary1.json", "one")
-	sig := append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...) // we're not interested in signature correctness
+	sig := append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...) // we're not interested in signature correctness
 	acc1, _ := keys.NewPrivateKey()
 	acc2, _ := keys.NewPrivateKey()
 	acc3, _ := keys.NewPrivateKey()
diff --git a/pkg/services/rpcsrv/client_test.go b/pkg/services/rpcsrv/client_test.go
index 247506d5b..aaf4b31f1 100644
--- a/pkg/services/rpcsrv/client_test.go
+++ b/pkg/services/rpcsrv/client_test.go
@@ -1089,7 +1089,7 @@ func TestSignAndPushP2PNotaryRequest(t *testing.T) {
 		err = ntr.Decrypt(notaryPass, w.Scrypt)
 		require.NoError(t, err)
 		req.FallbackTransaction.Scripts[0] = transaction.Witness{
-			InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, ntr.PrivateKey().SignHashable(uint32(testchain.Network()), req.FallbackTransaction)...),
+			InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, ntr.PrivateKey().SignHashable(uint32(testchain.Network()), req.FallbackTransaction)...),
 			VerificationScript: []byte{},
 		}
 		b := testchain.NewBlock(t, chain, 1, 0, req.FallbackTransaction)
diff --git a/pkg/services/rpcsrv/server_test.go b/pkg/services/rpcsrv/server_test.go
index e0e2ee86a..93f015121 100644
--- a/pkg/services/rpcsrv/server_test.go
+++ b/pkg/services/rpcsrv/server_test.go
@@ -1782,7 +1782,7 @@ func TestSubmitNotaryRequest(t *testing.T) {
 			},
 			Signers: []transaction.Signer{{Account: util.Uint160{1, 4, 7}}, {Account: util.Uint160{9, 8, 7}}},
 			Scripts: []transaction.Witness{
-				{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: make([]byte, 0)},
+				{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: make([]byte, 0)},
 				{InvocationScript: []byte{1, 2, 3}, VerificationScript: []byte{1, 2, 3}}},
 		}
 		p := &payload.P2PNotaryRequest{
@@ -1833,12 +1833,12 @@ func createValidNotaryRequest(chain *core.Blockchain, sender *keys.PrivateKey, n
 		},
 		Signers: []transaction.Signer{{Account: chain.GetNotaryContractScriptHash()}, {Account: sender.GetScriptHash()}},
 		Scripts: []transaction.Witness{
-			{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), 64}, make([]byte, 64)...), VerificationScript: []byte{}},
+			{InvocationScript: append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, make([]byte, keys.SignatureLen)...), VerificationScript: []byte{}},
 		},
 		NetworkFee: 2_0000_0000,
 	}
 	fallbackTx.Scripts = append(fallbackTx.Scripts, transaction.Witness{
-		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, sender.SignHashable(uint32(testchain.Network()), fallbackTx)...),
+		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, sender.SignHashable(uint32(testchain.Network()), fallbackTx)...),
 		VerificationScript: sender.PublicKey().GetVerificationScript(),
 	})
 	p := &payload.P2PNotaryRequest{
@@ -1846,7 +1846,7 @@ func createValidNotaryRequest(chain *core.Blockchain, sender *keys.PrivateKey, n
 		FallbackTransaction: fallbackTx,
 	}
 	p.Witness = transaction.Witness{
-		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), 64}, sender.SignHashable(uint32(testchain.Network()), p)...),
+		InvocationScript:   append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, sender.SignHashable(uint32(testchain.Network()), p)...),
 		VerificationScript: sender.PublicKey().GetVerificationScript(),
 	}
 	return p
diff --git a/pkg/smartcontract/context/item_test.go b/pkg/smartcontract/context/item_test.go
index 21108aa4d..767e510d4 100644
--- a/pkg/smartcontract/context/item_test.go
+++ b/pkg/smartcontract/context/item_test.go
@@ -43,11 +43,11 @@ func TestContextItem_MarshalJSON(t *testing.T) {
 		Script: []byte{1, 2, 3},
 		Parameters: []smartcontract.Parameter{{
 			Type:  smartcontract.SignatureType,
-			Value: random.Bytes(64),
+			Value: random.Bytes(keys.SignatureLen),
 		}},
 		Signatures: map[string][]byte{
-			hex.EncodeToString(priv1.PublicKey().Bytes()): random.Bytes(64),
-			hex.EncodeToString(priv2.PublicKey().Bytes()): random.Bytes(64),
+			hex.EncodeToString(priv1.PublicKey().Bytes()): random.Bytes(keys.SignatureLen),
+			hex.EncodeToString(priv2.PublicKey().Bytes()): random.Bytes(keys.SignatureLen),
 		},
 	}
 
diff --git a/pkg/smartcontract/manifest/event.go b/pkg/smartcontract/manifest/event.go
index 00a87e988..04a1f348d 100644
--- a/pkg/smartcontract/manifest/event.go
+++ b/pkg/smartcontract/manifest/event.go
@@ -2,6 +2,7 @@ package manifest
 
 import (
 	"errors"
+	"fmt"
 
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
@@ -60,3 +61,17 @@ func (e *Event) FromStackItem(item stackitem.Item) error {
 	}
 	return nil
 }
+
+// CheckCompliance checks compliance of the given array of items with the
+// current event.
+func (e *Event) CheckCompliance(items []stackitem.Item) error {
+	if len(items) != len(e.Parameters) {
+		return errors.New("mismatch between the number of parameters and items")
+	}
+	for i := range items {
+		if !e.Parameters[i].Type.Match(items[i]) {
+			return fmt.Errorf("parameter %d type mismatch: %s vs %s", i, e.Parameters[i].Type.String(), items[i].Type().String())
+		}
+	}
+	return nil
+}
diff --git a/pkg/smartcontract/manifest/event_test.go b/pkg/smartcontract/manifest/event_test.go
index 2e50bdd46..65b32183a 100644
--- a/pkg/smartcontract/manifest/event_test.go
+++ b/pkg/smartcontract/manifest/event_test.go
@@ -64,3 +64,13 @@ func TestEvent_FromStackItemErrors(t *testing.T) {
 		})
 	}
 }
+
+func TestEventCheckCompliance(t *testing.T) {
+	m := &Event{
+		Name:       "mur",
+		Parameters: []Parameter{{Name: "p1", Type: smartcontract.BoolType}},
+	}
+	require.Error(t, m.CheckCompliance([]stackitem.Item{}))
+	require.Error(t, m.CheckCompliance([]stackitem.Item{stackitem.Make("something")}))
+	require.NoError(t, m.CheckCompliance([]stackitem.Item{stackitem.Make(true)}))
+}
diff --git a/pkg/smartcontract/param_type.go b/pkg/smartcontract/param_type.go
index 5b36de52f..59d44ab04 100644
--- a/pkg/smartcontract/param_type.go
+++ b/pkg/smartcontract/param_type.go
@@ -38,6 +38,14 @@ const (
 	VoidType             ParamType = 0xff
 )
 
+// Lengths (in bytes) of fixed-size types.
+const (
+	Hash160Len   = util.Uint160Size
+	Hash256Len   = util.Uint256Size
+	PublicKeyLen = 33
+	SignatureLen = keys.SignatureLen
+)
+
 // fileBytesParamType is a string representation of `filebytes` parameter type used in cli.
 const fileBytesParamType string = "filebytes"
 
@@ -151,7 +159,7 @@ func (pt *ParamType) DecodeBinary(r *io.BinReader) {
 // public key is represented by 33-byte value while 32 bytes are used for integer
 // and a simple push+convert is used for boolean. Other types produce no code at all.
 func (pt ParamType) EncodeDefaultValue(w *io.BinWriter) {
-	var b [64]byte
+	var b [SignatureLen]byte
 
 	switch pt {
 	case AnyType, SignatureType, StringType, ByteArrayType:
@@ -161,15 +169,61 @@ func (pt ParamType) EncodeDefaultValue(w *io.BinWriter) {
 	case IntegerType:
 		emit.Instruction(w, opcode.PUSHINT256, b[:32])
 	case Hash160Type:
-		emit.Bytes(w, b[:20])
+		emit.Bytes(w, b[:Hash160Len])
 	case Hash256Type:
-		emit.Bytes(w, b[:32])
+		emit.Bytes(w, b[:Hash256Len])
 	case PublicKeyType:
-		emit.Bytes(w, b[:33])
+		emit.Bytes(w, b[:PublicKeyLen])
 	case ArrayType, MapType, InteropInterfaceType, VoidType:
 	}
 }
 
+func checkBytesWithLen(vt stackitem.Type, v stackitem.Item, l int) bool {
+	if vt == stackitem.AnyT {
+		return true
+	}
+	if vt != stackitem.ByteArrayT && vt != stackitem.BufferT {
+		return false
+	}
+	b, _ := v.TryBytes() // Can't fail, we know the type exactly.
+	return len(b) == l
+}
+
+func (pt ParamType) Match(v stackitem.Item) bool {
+	vt := v.Type()
+
+	// Pointer can't be matched at all.
+	if vt == stackitem.PointerT {
+		return false
+	}
+	switch pt {
+	case AnyType:
+		return true
+	case BoolType:
+		return vt == stackitem.BooleanT
+	case IntegerType:
+		return vt == stackitem.IntegerT
+	case ByteArrayType, StringType:
+		return vt == stackitem.ByteArrayT || vt == stackitem.BufferT || vt == stackitem.AnyT
+	case Hash160Type:
+		return checkBytesWithLen(vt, v, Hash160Len)
+	case Hash256Type:
+		return checkBytesWithLen(vt, v, Hash256Len)
+	case PublicKeyType:
+		return checkBytesWithLen(vt, v, PublicKeyLen)
+	case SignatureType:
+		return checkBytesWithLen(vt, v, SignatureLen)
+	case ArrayType:
+		return vt == stackitem.AnyT || vt == stackitem.ArrayT || vt == stackitem.StructT
+	case MapType:
+		return vt == stackitem.AnyT || vt == stackitem.MapT
+	case InteropInterfaceType:
+		return vt == stackitem.AnyT || vt == stackitem.InteropT
+	default:
+		return false
+	}
+}
+
 // ParseParamType is a user-friendly string to ParamType converter, it's
 // case-insensitive and makes the following conversions:
 //
@@ -228,7 +282,7 @@ func adjustValToType(typ ParamType, val string) (interface{}, error) {
 		if err != nil {
 			return nil, err
 		}
-		if len(b) != 64 {
+		if len(b) != SignatureLen {
 			return nil, errors.New("not a signature")
 		}
 		return b, nil
@@ -310,11 +364,11 @@ func inferParamType(val string) ParamType {
 	unhexed, err := hex.DecodeString(val)
 	if err == nil {
 		switch len(unhexed) {
-		case 20:
+		case Hash160Len:
 			return Hash160Type
-		case 32:
+		case Hash256Len:
 			return Hash256Type
-		case 64:
+		case SignatureLen:
 			return SignatureType
 		default:
 			return ByteArrayType
diff --git a/pkg/smartcontract/param_type_test.go b/pkg/smartcontract/param_type_test.go
index a9f52c11d..24ffa69fe 100644
--- a/pkg/smartcontract/param_type_test.go
+++ b/pkg/smartcontract/param_type_test.go
@@ -418,3 +418,58 @@ func TestConvertToStackitemType(t *testing.T) {
 		UnknownType.ConvertToStackitemType()
 	})
 }
+
+func TestParamTypeMatch(t *testing.T) {
+	for itm, pt := range map[stackitem.Item]ParamType{
+		&stackitem.Pointer{}:      BoolType,
+		&stackitem.Pointer{}:      MapType,
+		stackitem.Make(0):         BoolType,
+		stackitem.Make(0):         ByteArrayType,
+		stackitem.Make(0):         StringType,
+		stackitem.Make(false):     ByteArrayType,
+		stackitem.Make(true):      StringType,
+		stackitem.Make([]byte{1}): Hash160Type,
+		stackitem.Make([]byte{1}): Hash256Type,
+		stackitem.Make([]byte{1}): PublicKeyType,
+		stackitem.Make([]byte{1}): SignatureType,
+		stackitem.Make(0):         Hash160Type,
+		stackitem.Make(0):         Hash256Type,
+		stackitem.Make(0):         PublicKeyType,
+		stackitem.Make(0):         SignatureType,
+		stackitem.Make(0):         ArrayType,
+		stackitem.Make(0):         MapType,
+		stackitem.Make(0):         InteropInterfaceType,
+		stackitem.Make(0):         VoidType,
+	} {
+		require.Falsef(t, pt.Match(itm), "%s - %s", pt.String(), itm.String())
+	}
+	for itm, pt := range map[stackitem.Item]ParamType{
+		stackitem.Make(false):                      BoolType,
+		stackitem.Make(true):                       BoolType,
+		stackitem.Make(0):                          IntegerType,
+		stackitem.Make(100500):                     IntegerType,
+		stackitem.Make([]byte{1}):                  ByteArrayType,
+		stackitem.Make([]byte{1}):                  StringType,
+		stackitem.NewBuffer([]byte{1}):             ByteArrayType,
+		stackitem.NewBuffer([]byte{1}):             StringType,
+		stackitem.Null{}:                           ByteArrayType,
+		stackitem.Null{}:                           StringType,
+		stackitem.Make(util.Uint160{}.BytesBE()):   Hash160Type,
+		stackitem.Make(util.Uint256{}.BytesBE()):   Hash256Type,
+		stackitem.Null{}:                           Hash160Type,
+		stackitem.Null{}:                           Hash256Type,
+		stackitem.Make(make([]byte, PublicKeyLen)): PublicKeyType,
+		stackitem.Null{}:                           PublicKeyType,
+		stackitem.Make(make([]byte, SignatureLen)): SignatureType,
+		stackitem.Null{}:                           SignatureType,
+		stackitem.Make([]stackitem.Item{}):         ArrayType,
+		stackitem.NewStruct([]stackitem.Item{}):    ArrayType,
+		stackitem.Null{}:                           ArrayType,
+		stackitem.NewMap():                         MapType,
+		stackitem.Null{}:                           MapType,
+		stackitem.NewInterop(true):                 InteropInterfaceType,
+		stackitem.Null{}:                           InteropInterfaceType,
+	} {
+		require.Truef(t, pt.Match(itm), "%s - %s", pt.String(), itm.String())
+	}
+}
diff --git a/pkg/wallet/account.go b/pkg/wallet/account.go
index e1a7c30e3..4658d63f0 100644
--- a/pkg/wallet/account.go
+++ b/pkg/wallet/account.go
@@ -116,7 +116,7 @@ func (a *Account) SignTx(net netmode.Magic, t *transaction.Transaction) error {
 	}
 	sign := a.privateKey.SignHashable(uint32(net), t)
 
-	invoc := append([]byte{byte(opcode.PUSHDATA1), 64}, sign...)
+	invoc := append([]byte{byte(opcode.PUSHDATA1), keys.SignatureLen}, sign...)
 	if len(a.Contract.Parameters) == 1 {
 		t.Scripts[pos].InvocationScript = invoc
 	} else {