diff --git a/pkg/core/native/blocked_accounts.go b/pkg/core/native/blocked_accounts.go
deleted file mode 100644
index fb27ce34f..000000000
--- a/pkg/core/native/blocked_accounts.go
+++ /dev/null
@@ -1,53 +0,0 @@
-package native
-
-import (
-	"github.com/nspcc-dev/neo-go/pkg/io"
-	"github.com/nspcc-dev/neo-go/pkg/util"
-	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
-)
-
-// BlockedAccounts represents a slice of blocked accounts hashes.
-type BlockedAccounts []util.Uint160
-
-// Bytes returns serialized BlockedAccounts.
-func (ba *BlockedAccounts) Bytes() []byte {
-	w := io.NewBufBinWriter()
-	ba.EncodeBinary(w.BinWriter)
-	if w.Err != nil {
-		panic(w.Err)
-	}
-	return w.Bytes()
-}
-
-// EncodeBinary implements io.Serializable interface.
-func (ba *BlockedAccounts) EncodeBinary(w *io.BinWriter) {
-	w.WriteArray(*ba)
-}
-
-// BlockedAccountsFromBytes converts serialized BlockedAccounts to structure.
-func BlockedAccountsFromBytes(b []byte) (BlockedAccounts, error) {
-	ba := new(BlockedAccounts)
-	if len(b) == 0 {
-		return *ba, nil
-	}
-	r := io.NewBinReaderFromBuf(b)
-	ba.DecodeBinary(r)
-	if r.Err != nil {
-		return nil, r.Err
-	}
-	return *ba, nil
-}
-
-// DecodeBinary implements io.Serializable interface.
-func (ba *BlockedAccounts) DecodeBinary(r *io.BinReader) {
-	r.ReadArray(ba)
-}
-
-// ToStackItem converts BlockedAccounts to stackitem.Item
-func (ba *BlockedAccounts) ToStackItem() stackitem.Item {
-	result := make([]stackitem.Item, len(*ba))
-	for i, account := range *ba {
-		result[i] = stackitem.NewByteArray(account.BytesLE())
-	}
-	return stackitem.NewArray(result)
-}
diff --git a/pkg/core/native/blocked_accounts_test.go b/pkg/core/native/blocked_accounts_test.go
deleted file mode 100644
index 76709395e..000000000
--- a/pkg/core/native/blocked_accounts_test.go
+++ /dev/null
@@ -1,64 +0,0 @@
-package native
-
-import (
-	"encoding/json"
-	"testing"
-
-	"github.com/nspcc-dev/neo-go/pkg/internal/testserdes"
-	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
-	"github.com/nspcc-dev/neo-go/pkg/util"
-	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
-	"github.com/stretchr/testify/require"
-)
-
-func TestEncodeDecodeBinary(t *testing.T) {
-	expected := &BlockedAccounts{
-		util.Uint160{1, 2, 3},
-		util.Uint160{4, 5, 6},
-	}
-	actual := new(BlockedAccounts)
-	testserdes.EncodeDecodeBinary(t, expected, actual)
-
-	expected = &BlockedAccounts{}
-	actual = new(BlockedAccounts)
-	testserdes.EncodeDecodeBinary(t, expected, actual)
-}
-
-func TestBytesFromBytes(t *testing.T) {
-	expected := BlockedAccounts{
-		util.Uint160{1, 2, 3},
-		util.Uint160{4, 5, 6},
-	}
-	actual, err := BlockedAccountsFromBytes(expected.Bytes())
-	require.NoError(t, err)
-	require.Equal(t, expected, actual)
-
-	expected = BlockedAccounts{}
-	actual, err = BlockedAccountsFromBytes(expected.Bytes())
-	require.NoError(t, err)
-	require.Equal(t, expected, actual)
-}
-
-func TestToStackItem(t *testing.T) {
-	u1 := util.Uint160{1, 2, 3}
-	u2 := util.Uint160{4, 5, 6}
-	expected := BlockedAccounts{u1, u2}
-	actual := stackitem.NewArray([]stackitem.Item{
-		stackitem.NewByteArray(u1.BytesLE()),
-		stackitem.NewByteArray(u2.BytesLE()),
-	})
-	require.Equal(t, expected.ToStackItem(), actual)
-
-	expected = BlockedAccounts{}
-	actual = stackitem.NewArray([]stackitem.Item{})
-	require.Equal(t, expected.ToStackItem(), actual)
-}
-
-func TestMarshallJSON(t *testing.T) {
-	ba := &BlockedAccounts{}
-	p := smartcontract.ParameterFromStackItem(ba.ToStackItem(), make(map[stackitem.Item]bool))
-	actual, err := json.Marshal(p)
-	require.NoError(t, err)
-	expected := `{"type":"Array","value":[]}`
-	require.Equal(t, expected, string(actual))
-}
diff --git a/pkg/core/native/designate.go b/pkg/core/native/designate.go
index 8383d5c4f..6225e8cd1 100644
--- a/pkg/core/native/designate.go
+++ b/pkg/core/native/designate.go
@@ -30,6 +30,9 @@ type Designate struct {
 const (
 	designateContractID = -5
 	designateName       = "Designation"
+
+	// maxNodeCount is the maximum number of nodes to set the role for.
+	maxNodeCount = 32
 )
 
 // Role represents type of participant.
@@ -45,6 +48,7 @@ const (
 var (
 	ErrInvalidRole   = errors.New("invalid role")
 	ErrEmptyNodeList = errors.New("node list is empty")
+	ErrLargeNodeList = errors.New("node list is too large")
 )
 
 func isValidRole(r Role) bool {
@@ -162,9 +166,13 @@ func (s *Designate) designateAsRole(ic *interop.Context, args []stackitem.Item)
 
 // DesignateAsRole sets nodes for role r.
 func (s *Designate) DesignateAsRole(ic *interop.Context, r Role, pubs keys.PublicKeys) error {
-	if len(pubs) == 0 {
+	length := len(pubs)
+	if length == 0 {
 		return ErrEmptyNodeList
 	}
+	if length > maxNodeCount {
+		return ErrLargeNodeList
+	}
 	if !isValidRole(r) {
 		return ErrInvalidRole
 	}
diff --git a/pkg/core/native/gas_record.go b/pkg/core/native/gas_record.go
new file mode 100644
index 000000000..1c9121ac1
--- /dev/null
+++ b/pkg/core/native/gas_record.go
@@ -0,0 +1,13 @@
+package native
+
+import "math/big"
+
+// gasIndexPair contains block index together with generated gas per block.
+// It is used to cache NEO GASRecords.
+type gasIndexPair struct {
+	Index       uint32
+	GASPerBlock big.Int
+}
+
+// gasRecord contains history of gas per block changes. It is used only by NEO cache.
+type gasRecord []gasIndexPair
diff --git a/pkg/core/native/native_neo.go b/pkg/core/native/native_neo.go
index 43830e1cc..941c33899 100644
--- a/pkg/core/native/native_neo.go
+++ b/pkg/core/native/native_neo.go
@@ -2,7 +2,9 @@ package native
 
 import (
 	"crypto/elliptic"
+	"encoding/binary"
 	"errors"
+	"fmt"
 	"math/big"
 	"sort"
 	"strings"
@@ -189,13 +191,15 @@ func (n *NEO) Initialize(ic *interop.Context) error {
 	}
 	n.mint(ic, h, big.NewInt(NEOTotalSupply))
 
-	gr := &state.GASRecord{{Index: 0, GASPerBlock: *big.NewInt(5 * GASFactor)}}
-	n.gasPerBlock.Store(*gr)
-	n.gasPerBlockChanged.Store(false)
-	err = ic.DAO.PutStorageItem(n.ContractID, []byte{prefixGASPerBlock}, &state.StorageItem{Value: gr.Bytes()})
+	var index uint32 = 0
+	value := big.NewInt(5 * GASFactor)
+	err = n.putGASRecord(ic.DAO, index, value)
 	if err != nil {
 		return err
 	}
+	gr := &gasRecord{{Index: index, GASPerBlock: *value}}
+	n.gasPerBlock.Store(*gr)
+	n.gasPerBlockChanged.Store(false)
 	err = ic.DAO.PutStorageItem(n.ContractID, []byte{prefixVotersCount}, &state.StorageItem{Value: []byte{}})
 	if err != nil {
 		return err
@@ -217,9 +221,8 @@ func (n *NEO) InitializeCache(bc blockchainer.Blockchainer, d dao.DAO) error {
 		return err
 	}
 
-	var gr state.GASRecord
-	si = d.GetStorageItem(n.ContractID, []byte{prefixGASPerBlock})
-	if err := gr.FromBytes(si.Value); err != nil {
+	gr, err := n.getSortedGASRecordFromDAO(d)
+	if err != nil {
 		return err
 	}
 	n.gasPerBlock.Store(gr)
@@ -293,7 +296,10 @@ func (n *NEO) PostPersist(ic *interop.Context) error {
 // OnPersistEnd updates cached values if they've been changed.
 func (n *NEO) OnPersistEnd(d dao.DAO) {
 	if n.gasPerBlockChanged.Load().(bool) {
-		gr := n.getGASRecordFromDAO(d)
+		gr, err := n.getSortedGASRecordFromDAO(d)
+		if err != nil {
+			panic(err)
+		}
 		n.gasPerBlock.Store(gr)
 		n.gasPerBlockChanged.Store(false)
 	}
@@ -365,20 +371,41 @@ func (n *NEO) getGASPerBlock(ic *interop.Context, _ []stackitem.Item) stackitem.
 	return stackitem.NewBigInteger(gas)
 }
 
-func (n *NEO) getGASRecordFromDAO(d dao.DAO) state.GASRecord {
-	var gr state.GASRecord
-	si := d.GetStorageItem(n.ContractID, []byte{prefixGASPerBlock})
-	_ = gr.FromBytes(si.Value)
-	return gr
+func (n *NEO) getSortedGASRecordFromDAO(d dao.DAO) (gasRecord, error) {
+	grMap, err := d.GetStorageItemsWithPrefix(n.ContractID, []byte{prefixGASPerBlock})
+	if err != nil {
+		return gasRecord{}, fmt.Errorf("failed to get gas records from storage: %w", err)
+	}
+	var (
+		i  int
+		gr = make(gasRecord, len(grMap))
+	)
+	for indexBytes, gasValue := range grMap {
+		gr[i] = gasIndexPair{
+			Index:       binary.BigEndian.Uint32([]byte(indexBytes)),
+			GASPerBlock: *bigint.FromBytes(gasValue.Value),
+		}
+		i++
+	}
+	sort.Slice(gr, func(i, j int) bool {
+		return gr[i].Index < gr[j].Index
+	})
+	return gr, nil
 }
 
 // GetGASPerBlock returns gas generated for block with provided index.
 func (n *NEO) GetGASPerBlock(d dao.DAO, index uint32) *big.Int {
-	var gr state.GASRecord
+	var (
+		gr  gasRecord
+		err error
+	)
 	if n.gasPerBlockChanged.Load().(bool) {
-		gr = n.getGASRecordFromDAO(d)
+		gr, err = n.getSortedGASRecordFromDAO(d)
+		if err != nil {
+			panic(err)
+		}
 	} else {
-		gr = n.gasPerBlock.Load().(state.GASRecord)
+		gr = n.gasPerBlock.Load().(gasRecord)
 	}
 	for i := len(gr) - 1; i >= 0; i-- {
 		if gr[i].Index <= index {
@@ -413,21 +440,8 @@ func (n *NEO) SetGASPerBlock(ic *interop.Context, index uint32, gas *big.Int) (b
 	if err != nil || !ok {
 		return ok, err
 	}
-	si := ic.DAO.GetStorageItem(n.ContractID, []byte{prefixGASPerBlock})
-	var gr state.GASRecord
-	if err := gr.FromBytes(si.Value); err != nil {
-		return false, err
-	}
-	if len(gr) > 0 && gr[len(gr)-1].Index == index {
-		gr[len(gr)-1].GASPerBlock = *gas
-	} else {
-		gr = append(gr, state.GASIndexPair{
-			Index:       index,
-			GASPerBlock: *gas,
-		})
-	}
 	n.gasPerBlockChanged.Store(true)
-	return true, ic.DAO.PutStorageItem(n.ContractID, []byte{prefixGASPerBlock}, &state.StorageItem{Value: gr.Bytes()})
+	return true, n.putGASRecord(ic.DAO, index, gas)
 }
 
 // CalculateBonus calculates amount of gas generated for holding `value` NEO from start to end block.
@@ -437,10 +451,17 @@ func (n *NEO) CalculateBonus(ic *interop.Context, value *big.Int, start, end uin
 	} else if value.Sign() < 0 {
 		return nil, errors.New("negative value")
 	}
-	si := ic.DAO.GetStorageItem(n.ContractID, []byte{prefixGASPerBlock})
-	var gr state.GASRecord
-	if err := gr.FromBytes(si.Value); err != nil {
-		return nil, err
+	var (
+		gr  gasRecord
+		err error
+	)
+	if !n.gasPerBlockChanged.Load().(bool) {
+		gr = n.gasPerBlock.Load().(gasRecord)
+	} else {
+		gr, err = n.getSortedGASRecordFromDAO(ic.DAO)
+		if err != nil {
+			return nil, err
+		}
 	}
 	var sum, tmp big.Int
 	for i := len(gr) - 1; i >= 0; i-- {
@@ -751,3 +772,15 @@ func toPublicKey(s stackitem.Item) *keys.PublicKey {
 	}
 	return pub
 }
+
+// putGASRecord is a helper which creates key and puts GASPerBlock value into the storage.
+func (n *NEO) putGASRecord(dao dao.DAO, index uint32, value *big.Int) error {
+	key := make([]byte, 5)
+	key[0] = prefixGASPerBlock
+	binary.BigEndian.PutUint32(key[1:], index)
+	si := &state.StorageItem{
+		Value:   bigint.ToBytes(value),
+		IsConst: false,
+	}
+	return dao.PutStorageItem(n.ContractID, key, si)
+}
diff --git a/pkg/core/native/oracle.go b/pkg/core/native/oracle.go
index abe3b7228..dfcc47287 100644
--- a/pkg/core/native/oracle.go
+++ b/pkg/core/native/oracle.go
@@ -3,6 +3,7 @@ package native
 import (
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"math/big"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/dao"
@@ -42,6 +43,8 @@ const (
 	maxFilterLength   = 128
 	maxCallbackLength = 32
 	maxUserDataLength = 512
+	// maxRequestsCount is the maximum number of requests per URL
+	maxRequestsCount = 256
 
 	oracleRequestPrice = 5000_0000
 )
@@ -329,6 +332,9 @@ func (o *Oracle) PutRequestInternal(id uint64, req *state.OracleRequest, d dao.D
 	if err := o.getSerializableFromDAO(d, key, lst); err != nil && !errors.Is(err, storage.ErrKeyNotFound) {
 		return err
 	}
+	if len(*lst) >= maxRequestsCount {
+		return fmt.Errorf("there are too many pending requests for %s url", req.URL)
+	}
 	*lst = append(*lst, id)
 	si := &state.StorageItem{Value: lst.Bytes()}
 	return d.PutStorageItem(o.ContractID, key, si)
diff --git a/pkg/core/native/policy.go b/pkg/core/native/policy.go
index d0e8f7533..22a53cfbb 100644
--- a/pkg/core/native/policy.go
+++ b/pkg/core/native/policy.go
@@ -2,7 +2,6 @@ package native
 
 import (
 	"encoding/binary"
-	"errors"
 	"fmt"
 	"math/big"
 	"sort"
@@ -34,6 +33,9 @@ const (
 	minBlockSystemFee = 4007600
 	// maxFeePerByte is the maximum allowed fee per byte value.
 	maxFeePerByte = 100_000_000
+
+	// blockedAccountPrefix is a prefix used to store blocked account.
+	blockedAccountPrefix = 15
 )
 
 var (
@@ -43,8 +45,6 @@ var (
 	// feePerByteKey is a key used to store the minimum fee per byte for
 	// transaction.
 	feePerByteKey = []byte{10}
-	// blockedAccountsKey is a key used to store the list of blocked accounts.
-	blockedAccountsKey = []byte{15}
 	// maxBlockSizeKey is a key used to store the maximum block size value.
 	maxBlockSizeKey = []byte{12}
 	// maxBlockSystemFeeKey is a key used to store the maximum block system fee value.
@@ -64,7 +64,7 @@ type Policy struct {
 	feePerByte              int64
 	maxBlockSystemFee       int64
 	maxVerificationGas      int64
-	blockedAccounts         BlockedAccounts
+	blockedAccounts         []util.Uint160
 }
 
 var _ interop.Contract = (*Policy)(nil)
@@ -88,8 +88,9 @@ func newPolicy() *Policy {
 	md = newMethodAndPrice(p.getFeePerByte, 1000000, smartcontract.AllowStates)
 	p.AddMethod(md, desc, true)
 
-	desc = newDescriptor("getBlockedAccounts", smartcontract.ArrayType)
-	md = newMethodAndPrice(p.getBlockedAccounts, 1000000, smartcontract.AllowStates)
+	desc = newDescriptor("isBlocked", smartcontract.BoolType,
+		manifest.NewParameter("account", smartcontract.Hash160Type))
+	md = newMethodAndPrice(p.isBlocked, 1000000, smartcontract.AllowStates)
 	p.AddMethod(md, desc, true)
 
 	desc = newDescriptor("getMaxBlockSystemFee", smartcontract.IntegerType)
@@ -175,13 +176,6 @@ func (p *Policy) Initialize(ic *interop.Context) error {
 		return err
 	}
 
-	ba := new(BlockedAccounts)
-	si.Value = ba.Bytes()
-	err = ic.DAO.PutStorageItem(p.ContractID, blockedAccountsKey, si)
-	if err != nil {
-		return err
-	}
-
 	p.isValid = true
 	p.maxTransactionsPerBlock = defaultMaxTransactionsPerBlock
 	p.maxBlockSize = defaultMaxBlockSize
@@ -220,15 +214,21 @@ func (p *Policy) OnPersistEnd(dao dao.DAO) error {
 
 	p.maxVerificationGas = defaultMaxVerificationGas
 
-	si := dao.GetStorageItem(p.ContractID, blockedAccountsKey)
-	if si == nil {
-		return errors.New("BlockedAccounts uninitialized")
-	}
-	ba, err := BlockedAccountsFromBytes(si.Value)
+	p.blockedAccounts = make([]util.Uint160, 0)
+	siMap, err := dao.GetStorageItemsWithPrefix(p.ContractID, []byte{blockedAccountPrefix})
 	if err != nil {
-		return fmt.Errorf("failed to decode BlockedAccounts from bytes: %w", err)
+		return fmt.Errorf("failed to get blocked accounts from storage: %w", err)
 	}
-	p.blockedAccounts = ba
+	for key := range siMap {
+		hash, err := util.Uint160DecodeBytesBE([]byte(key))
+		if err != nil {
+			return fmt.Errorf("failed to decode blocked account hash: %w", err)
+		}
+		p.blockedAccounts = append(p.blockedAccounts, hash)
+	}
+	sort.Slice(p.blockedAccounts, func(i, j int) bool {
+		return p.blockedAccounts[i].Less(p.blockedAccounts[j])
+	})
 
 	p.isValid = true
 	return nil
@@ -306,32 +306,28 @@ func (p *Policy) GetMaxBlockSystemFeeInternal(dao dao.DAO) int64 {
 	return p.getInt64WithKey(dao, maxBlockSystemFeeKey)
 }
 
-// getBlockedAccounts is Policy contract method and returns list of blocked
-// accounts hashes.
-func (p *Policy) getBlockedAccounts(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
-	ba, err := p.GetBlockedAccountsInternal(ic.DAO)
-	if err != nil {
-		panic(err)
-	}
-	return ba.ToStackItem()
+// isBlocked is Policy contract method and checks whether provided account is blocked.
+func (p *Policy) isBlocked(ic *interop.Context, args []stackitem.Item) stackitem.Item {
+	hash := toUint160(args[0])
+	return stackitem.NewBool(p.IsBlockedInternal(ic.DAO, hash))
 }
 
-// GetBlockedAccountsInternal returns list of blocked accounts hashes.
-func (p *Policy) GetBlockedAccountsInternal(dao dao.DAO) (BlockedAccounts, error) {
+// IsBlockedInternal checks whether provided account is blocked
+func (p *Policy) IsBlockedInternal(dao dao.DAO, hash util.Uint160) bool {
 	p.lock.RLock()
 	defer p.lock.RUnlock()
 	if p.isValid {
-		return p.blockedAccounts, nil
+		length := len(p.blockedAccounts)
+		i := sort.Search(length, func(i int) bool {
+			return !p.blockedAccounts[i].Less(hash)
+		})
+		if length != 0 && i != length && p.blockedAccounts[i].Equals(hash) {
+			return true
+		}
+		return false
 	}
-	si := dao.GetStorageItem(p.ContractID, blockedAccountsKey)
-	if si == nil {
-		return nil, errors.New("BlockedAccounts uninitialized")
-	}
-	ba, err := BlockedAccountsFromBytes(si.Value)
-	if err != nil {
-		return nil, err
-	}
-	return ba, nil
+	key := append([]byte{blockedAccountPrefix}, hash.BytesBE()...)
+	return dao.GetStorageItem(p.ContractID, key) != nil
 }
 
 // setMaxTransactionsPerBlock is Policy contract method and  sets the upper limit
@@ -437,30 +433,15 @@ func (p *Policy) blockAccount(ic *interop.Context, args []stackitem.Item) stacki
 	if !ok {
 		return stackitem.NewBool(false)
 	}
-	value := toUint160(args[0])
-	si := ic.DAO.GetStorageItem(p.ContractID, blockedAccountsKey)
-	if si == nil {
-		panic("BlockedAccounts uninitialized")
-	}
-	ba, err := BlockedAccountsFromBytes(si.Value)
-	if err != nil {
-		panic(err)
-	}
-	indexToInsert := sort.Search(len(ba), func(i int) bool {
-		return !ba[i].Less(value)
-	})
-	ba = append(ba, value)
-	if indexToInsert != len(ba)-1 && ba[indexToInsert].Equals(value) {
+	hash := toUint160(args[0])
+	if p.IsBlockedInternal(ic.DAO, hash) {
 		return stackitem.NewBool(false)
 	}
-	if len(ba) > 1 {
-		copy(ba[indexToInsert+1:], ba[indexToInsert:])
-		ba[indexToInsert] = value
-	}
+	key := append([]byte{blockedAccountPrefix}, hash.BytesBE()...)
 	p.lock.Lock()
 	defer p.lock.Unlock()
-	err = ic.DAO.PutStorageItem(p.ContractID, blockedAccountsKey, &state.StorageItem{
-		Value: ba.Bytes(),
+	err = ic.DAO.PutStorageItem(p.ContractID, key, &state.StorageItem{
+		Value: []byte{0x01},
 	})
 	if err != nil {
 		panic(err)
@@ -479,27 +460,14 @@ func (p *Policy) unblockAccount(ic *interop.Context, args []stackitem.Item) stac
 	if !ok {
 		return stackitem.NewBool(false)
 	}
-	value := toUint160(args[0])
-	si := ic.DAO.GetStorageItem(p.ContractID, blockedAccountsKey)
-	if si == nil {
-		panic("BlockedAccounts uninitialized")
-	}
-	ba, err := BlockedAccountsFromBytes(si.Value)
-	if err != nil {
-		panic(err)
-	}
-	indexToRemove := sort.Search(len(ba), func(i int) bool {
-		return !ba[i].Less(value)
-	})
-	if indexToRemove == len(ba) || !ba[indexToRemove].Equals(value) {
+	hash := toUint160(args[0])
+	if !p.IsBlockedInternal(ic.DAO, hash) {
 		return stackitem.NewBool(false)
 	}
-	ba = append(ba[:indexToRemove], ba[indexToRemove+1:]...)
+	key := append([]byte{blockedAccountPrefix}, hash.BytesBE()...)
 	p.lock.Lock()
 	defer p.lock.Unlock()
-	err = ic.DAO.PutStorageItem(p.ContractID, blockedAccountsKey, &state.StorageItem{
-		Value: ba.Bytes(),
-	})
+	err = ic.DAO.DeleteStorageItem(p.ContractID, key)
 	if err != nil {
 		panic(err)
 	}
@@ -555,18 +523,9 @@ func (p *Policy) checkValidators(ic *interop.Context) (bool, error) {
 // like not being signed by blocked account or not exceeding block-level system
 // fee limit.
 func (p *Policy) CheckPolicy(d dao.DAO, tx *transaction.Transaction) error {
-	ba, err := p.GetBlockedAccountsInternal(d)
-	if err != nil {
-		return fmt.Errorf("unable to get blocked accounts list: %w", err)
-	}
-	if len(ba) > 0 {
-		for _, signer := range tx.Signers {
-			i := sort.Search(len(ba), func(i int) bool {
-				return !ba[i].Less(signer.Account)
-			})
-			if i != len(ba) && ba[i].Equals(signer.Account) {
-				return fmt.Errorf("account %s is blocked", signer.Account.StringLE())
-			}
+	for _, signer := range tx.Signers {
+		if p.IsBlockedInternal(d, signer.Account) {
+			return fmt.Errorf("account %s is blocked", signer.Account.StringLE())
 		}
 	}
 	maxBlockSystemFee := p.GetMaxBlockSystemFeeInternal(d)
diff --git a/pkg/core/native_designate_test.go b/pkg/core/native_designate_test.go
index c15098a59..83d7e31c1 100644
--- a/pkg/core/native_designate_test.go
+++ b/pkg/core/native_designate_test.go
@@ -92,6 +92,9 @@ func TestDesignate_DesignateAsRole(t *testing.T) {
 	err = des.DesignateAsRole(ic, native.RoleOracle, keys.PublicKeys{})
 	require.True(t, errors.Is(err, native.ErrEmptyNodeList), "got: %v", err)
 
+	err = des.DesignateAsRole(ic, native.RoleOracle, make(keys.PublicKeys, 32+1))
+	require.True(t, errors.Is(err, native.ErrLargeNodeList), "got: %v", err)
+
 	priv, err := keys.NewPrivateKey()
 	require.NoError(t, err)
 	pub := priv.PublicKey()
diff --git a/pkg/core/native_policy_test.go b/pkg/core/native_policy_test.go
index 9a5c9f777..4312efdb4 100644
--- a/pkg/core/native_policy_test.go
+++ b/pkg/core/native_policy_test.go
@@ -2,7 +2,6 @@ package core
 
 import (
 	"math/big"
-	"sort"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
@@ -10,6 +9,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
+	"github.com/nspcc-dev/neo-go/pkg/internal/random"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/network/payload"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -162,16 +162,15 @@ func TestBlockedAccounts(t *testing.T) {
 	defer chain.Close()
 	account := util.Uint160{1, 2, 3}
 
-	t.Run("get, internal method", func(t *testing.T) {
-		accounts, err := chain.contracts.Policy.GetBlockedAccountsInternal(chain.dao)
-		require.NoError(t, err)
-		require.Equal(t, native.BlockedAccounts{}, accounts)
+	t.Run("isBlocked, internal method", func(t *testing.T) {
+		isBlocked := chain.contracts.Policy.IsBlockedInternal(chain.dao, random.Uint160())
+		require.Equal(t, false, isBlocked)
 	})
 
-	t.Run("get, contract method", func(t *testing.T) {
-		res, err := invokeNativePolicyMethod(chain, "getBlockedAccounts")
+	t.Run("isBlocked, contract method", func(t *testing.T) {
+		res, err := invokeNativePolicyMethod(chain, "isBlocked", random.Uint160())
 		require.NoError(t, err)
-		checkResult(t, res, stackitem.NewArray([]stackitem.Item{}))
+		checkResult(t, res, stackitem.NewBool(false))
 		require.NoError(t, chain.persist())
 	})
 
@@ -180,18 +179,16 @@ func TestBlockedAccounts(t *testing.T) {
 		require.NoError(t, err)
 		checkResult(t, res, stackitem.NewBool(true))
 
-		accounts, err := chain.contracts.Policy.GetBlockedAccountsInternal(chain.dao)
-		require.NoError(t, err)
-		require.Equal(t, native.BlockedAccounts{account}, accounts)
+		isBlocked := chain.contracts.Policy.IsBlockedInternal(chain.dao, account)
+		require.Equal(t, isBlocked, true)
 		require.NoError(t, chain.persist())
 
 		res, err = invokeNativePolicyMethod(chain, "unblockAccount", account.BytesBE())
 		require.NoError(t, err)
 		checkResult(t, res, stackitem.NewBool(true))
 
-		accounts, err = chain.contracts.Policy.GetBlockedAccountsInternal(chain.dao)
-		require.NoError(t, err)
-		require.Equal(t, native.BlockedAccounts{}, accounts)
+		isBlocked = chain.contracts.Policy.IsBlockedInternal(chain.dao, account)
+		require.Equal(t, false, isBlocked)
 		require.NoError(t, chain.persist())
 	})
 
@@ -220,28 +217,6 @@ func TestBlockedAccounts(t *testing.T) {
 		checkResult(t, res, stackitem.NewBool(false))
 		require.NoError(t, chain.persist())
 	})
-
-	t.Run("sorted", func(t *testing.T) {
-		accounts := []util.Uint160{
-			{2, 3, 4},
-			{4, 5, 6},
-			{3, 4, 5},
-			{1, 2, 3},
-		}
-		for _, acc := range accounts {
-			res, err := invokeNativePolicyMethod(chain, "blockAccount", acc.BytesBE())
-			require.NoError(t, err)
-			checkResult(t, res, stackitem.NewBool(true))
-			require.NoError(t, chain.persist())
-		}
-
-		sort.Slice(accounts, func(i, j int) bool {
-			return accounts[i].Less(accounts[j])
-		})
-		actual, err := chain.contracts.Policy.GetBlockedAccountsInternal(chain.dao)
-		require.NoError(t, err)
-		require.Equal(t, native.BlockedAccounts(accounts), actual)
-	})
 }
 
 func invokeNativePolicyMethod(chain *Blockchain, method string, args ...interface{}) (*state.AppExecResult, error) {
diff --git a/pkg/core/state/native_state.go b/pkg/core/state/native_state.go
index c6cfcd1ff..408daddb5 100644
--- a/pkg/core/state/native_state.go
+++ b/pkg/core/state/native_state.go
@@ -2,7 +2,6 @@ package state
 
 import (
 	"crypto/elliptic"
-	"errors"
 	"math/big"
 
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
@@ -22,76 +21,6 @@ type NEOBalanceState struct {
 	VoteTo        *keys.PublicKey
 }
 
-// GASIndexPair contains block index together with generated gas per block.
-type GASIndexPair struct {
-	Index       uint32
-	GASPerBlock big.Int
-}
-
-// GASRecord contains history of gas per block changes.
-type GASRecord []GASIndexPair
-
-// Bytes serializes g to []byte.
-func (g *GASRecord) Bytes() []byte {
-	w := io.NewBufBinWriter()
-	g.EncodeBinary(w.BinWriter)
-	return w.Bytes()
-}
-
-// FromBytes deserializes g from data.
-func (g *GASRecord) FromBytes(data []byte) error {
-	r := io.NewBinReaderFromBuf(data)
-	g.DecodeBinary(r)
-	return r.Err
-}
-
-// DecodeBinary implements io.Serializable.
-func (g *GASRecord) DecodeBinary(r *io.BinReader) {
-	item := stackitem.DecodeBinaryStackItem(r)
-	if r.Err == nil {
-		r.Err = g.fromStackItem(item)
-	}
-}
-
-// EncodeBinary implements io.Serializable.
-func (g *GASRecord) EncodeBinary(w *io.BinWriter) {
-	item := g.toStackItem()
-	stackitem.EncodeBinaryStackItem(item, w)
-}
-
-// toStackItem converts GASRecord to a stack item.
-func (g *GASRecord) toStackItem() stackitem.Item {
-	items := make([]stackitem.Item, len(*g))
-	for i := range items {
-		items[i] = stackitem.NewStruct([]stackitem.Item{
-			stackitem.NewBigInteger(big.NewInt(int64((*g)[i].Index))),
-			stackitem.NewBigInteger(&(*g)[i].GASPerBlock),
-		})
-	}
-	return stackitem.NewArray(items)
-}
-
-var errInvalidFormat = errors.New("invalid item format")
-
-// fromStackItem converts item to a GASRecord.
-func (g *GASRecord) fromStackItem(item stackitem.Item) error {
-	arr, ok := item.Value().([]stackitem.Item)
-	if !ok {
-		return errInvalidFormat
-	}
-	for i := range arr {
-		s, ok := arr[i].Value().([]stackitem.Item)
-		if !ok || len(s) != 2 || s[0].Type() != stackitem.IntegerT || s[1].Type() != stackitem.IntegerT {
-			return errInvalidFormat
-		}
-		*g = append(*g, GASIndexPair{
-			Index:       uint32(s[0].Value().(*big.Int).Uint64()),
-			GASPerBlock: *s[1].Value().(*big.Int),
-		})
-	}
-	return nil
-}
-
 // NEP5BalanceStateFromBytes converts serialized NEP5BalanceState to structure.
 func NEP5BalanceStateFromBytes(b []byte) (*NEP5BalanceState, error) {
 	balance := new(NEP5BalanceState)
diff --git a/pkg/core/state/native_state_test.go b/pkg/core/state/native_state_test.go
deleted file mode 100644
index 920a7f331..000000000
--- a/pkg/core/state/native_state_test.go
+++ /dev/null
@@ -1,40 +0,0 @@
-package state
-
-import (
-	"math/big"
-	"testing"
-
-	"github.com/nspcc-dev/neo-go/pkg/internal/testserdes"
-	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
-	"github.com/stretchr/testify/require"
-)
-
-func TestGASRecord_EncodeBinary(t *testing.T) {
-	expected := &GASRecord{
-		GASIndexPair{
-			Index:       1,
-			GASPerBlock: *big.NewInt(123),
-		},
-		GASIndexPair{
-			Index:       2,
-			GASPerBlock: *big.NewInt(7),
-		},
-	}
-	testserdes.EncodeDecodeBinary(t, expected, new(GASRecord))
-}
-
-func TestGASRecord_fromStackItem(t *testing.T) {
-	t.Run("NotArray", func(t *testing.T) {
-		item := stackitem.Null{}
-		require.Error(t, new(GASRecord).fromStackItem(item))
-	})
-	t.Run("InvalidFormat", func(t *testing.T) {
-		item := stackitem.NewArray([]stackitem.Item{
-			stackitem.NewStruct([]stackitem.Item{
-				stackitem.NewBigInteger(big.NewInt(1)),
-				stackitem.NewBool(true),
-			}),
-		})
-		require.Error(t, new(GASRecord).fromStackItem(item))
-	})
-}
diff --git a/pkg/rpc/client/policy.go b/pkg/rpc/client/policy.go
index 7e6aa59bf..efffcd492 100644
--- a/pkg/rpc/client/policy.go
+++ b/pkg/rpc/client/policy.go
@@ -3,7 +3,6 @@ package client
 import (
 	"fmt"
 
-	"github.com/nspcc-dev/neo-go/pkg/core/native"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
@@ -41,39 +40,28 @@ func (c *Client) invokeNativePolicyMethod(operation string) (int64, error) {
 	return topIntFromStack(result.Stack)
 }
 
-// GetBlockedAccounts invokes `getBlockedAccounts` method on a native Policy contract.
-func (c *Client) GetBlockedAccounts() (native.BlockedAccounts, error) {
-	result, err := c.InvokeFunction(PolicyContractHash, "getBlockedAccounts", []smartcontract.Parameter{}, nil)
+// IsBlocked invokes `isBlocked` method on native Policy contract.
+func (c *Client) IsBlocked(hash util.Uint160) (bool, error) {
+	result, err := c.InvokeFunction(PolicyContractHash, "isBlocked", []smartcontract.Parameter{{
+		Type:  smartcontract.Hash160Type,
+		Value: hash,
+	}}, nil)
 	if err != nil {
-		return nil, err
+		return false, err
 	}
 	err = getInvocationError(result)
 	if err != nil {
-		return nil, fmt.Errorf("failed to get blocked accounts: %w", err)
+		return false, fmt.Errorf("failed to check if account is blocked: %w", err)
 	}
-	return topBlockedAccountsFromStack(result.Stack)
+	return topBoolFromStack(result.Stack)
 }
 
-func topBlockedAccountsFromStack(st []stackitem.Item) (native.BlockedAccounts, error) {
+// topBoolFromStack returns the top boolean value from stack
+func topBoolFromStack(st []stackitem.Item) (bool, error) {
 	index := len(st) - 1 // top stack element is last in the array
-	var (
-		ba  native.BlockedAccounts
-		err error
-	)
-	items, ok := st[index].Value().([]stackitem.Item)
+	result, ok := st[index].Value().(bool)
 	if !ok {
-		return nil, fmt.Errorf("invalid stack item type: %s", st[index].Type())
+		return false, fmt.Errorf("invalid stack item type: %s", st[index].Type())
 	}
-	ba = make(native.BlockedAccounts, len(items))
-	for i, account := range items {
-		val, ok := account.Value().([]byte)
-		if !ok {
-			return nil, fmt.Errorf("invalid array element: %s", account.Type())
-		}
-		ba[i], err = util.Uint160DecodeBytesLE(val)
-		if err != nil {
-			return nil, err
-		}
-	}
-	return ba, nil
+	return result, nil
 }
diff --git a/pkg/rpc/client/rpc_test.go b/pkg/rpc/client/rpc_test.go
index 1be95bba9..d1913a12f 100644
--- a/pkg/rpc/client/rpc_test.go
+++ b/pkg/rpc/client/rpc_test.go
@@ -16,7 +16,6 @@ import (
 	"github.com/gorilla/websocket"
 	"github.com/nspcc-dev/neo-go/pkg/config/netmode"
 	"github.com/nspcc-dev/neo-go/pkg/core/block"
-	"github.com/nspcc-dev/neo-go/pkg/core/native"
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
@@ -378,15 +377,15 @@ var rpcClientTestCases = map[string][]rpcClientTestCase{
 			},
 		},
 	},
-	"getBlockedAccounts": {
+	"isBlocked": {
 		{
 			name: "positive",
 			invoke: func(c *Client) (interface{}, error) {
-				return c.GetBlockedAccounts()
+				return c.IsBlocked(util.Uint160{1, 2, 3})
 			},
-			serverResponse: `{"id":1,"jsonrpc":"2.0","result":{"state":"HALT","gasconsumed":"2007390","script":"EMAMEmdldEJsb2NrZWRBY2NvdW50cwwUmmGkbuyXuJMG186B8VtGIJHQCTJBYn1bUg==","stack":[{"type":"Array","value":[]}],"tx":null}}`,
+			serverResponse: `{"id":1,"jsonrpc":"2.0","result":{"state":"HALT","gasconsumed":"2007390","script":"EMAMEmdldEJsb2NrZWRBY2NvdW50cwwUmmGkbuyXuJMG186B8VtGIJHQCTJBYn1bUg==","stack":[{"type":"Boolean","value":false}],"tx":null}}`,
 			result: func(c *Client) interface{} {
-				return native.BlockedAccounts{}
+				return false
 			},
 		},
 	},