diff --git a/CHANGELOG.md b/CHANGELOG.md
index ae8d9030..1488390a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ This document outlines major changes between releases.
 New features:
 
 Behaviour changes:
+ * simplify PublicKey interface (#114)
+ * remove WithKeyPair callback from dBFT (#114)
 
 Improvements:
 
diff --git a/config.go b/config.go
index 5de4e58f..c34ac35b 100644
--- a/config.go
+++ b/config.go
@@ -1,7 +1,6 @@
 package dbft
 
 import (
-	"bytes"
 	"errors"
 	"time"
 
@@ -137,30 +136,6 @@ func checkConfig[H Hash](cfg *Config[H]) error {
 	return nil
 }
 
-// WithKeyPair sets GetKeyPair to a function returning default key pair
-// if it is present in a list of validators.
-func WithKeyPair[H Hash](priv PrivateKey, pub PublicKey) func(config *Config[H]) {
-	myPub, err := pub.MarshalBinary()
-	if err != nil {
-		return nil
-	}
-
-	return func(cfg *Config[H]) {
-		cfg.GetKeyPair = func(ps []PublicKey) (int, PrivateKey, PublicKey) {
-			for i := range ps {
-				pi, err := ps[i].MarshalBinary()
-				if err != nil {
-					continue
-				} else if bytes.Equal(myPub, pi) {
-					return i, priv, pub
-				}
-			}
-
-			return -1, nil, nil
-		}
-	}
-}
-
 // WithGetKeyPair sets GetKeyPair.
 func WithGetKeyPair[H Hash](f func(pubs []PublicKey) (int, PrivateKey, PublicKey)) func(config *Config[H]) {
 	return func(cfg *Config[H]) {
diff --git a/dbft_test.go b/dbft_test.go
index 2adb1d52..86fe3c89 100644
--- a/dbft_test.go
+++ b/dbft_test.go
@@ -418,7 +418,9 @@ func TestDBFT_Invalid(t *testing.T) {
 	require.NotNil(t, priv)
 	require.NotNil(t, pub)
 
-	opts := []func(*dbft.Config[crypto.Uint256]){dbft.WithKeyPair[crypto.Uint256](priv, pub)}
+	opts := []func(*dbft.Config[crypto.Uint256]){dbft.WithGetKeyPair[crypto.Uint256](func(_ []dbft.PublicKey) (int, dbft.PrivateKey, dbft.PublicKey) {
+		return -1, nil, nil
+	})}
 	t.Run("without Timer", func(t *testing.T) {
 		_, err := dbft.New(opts...)
 		require.Error(t, err)
@@ -829,7 +831,9 @@ func (s *testState) getOptions() []func(*dbft.Config[crypto.Uint256]) {
 		dbft.WithCurrentHeight[crypto.Uint256](func() uint32 { return s.currHeight }),
 		dbft.WithCurrentBlockHash[crypto.Uint256](func() crypto.Uint256 { return s.currHash }),
 		dbft.WithGetValidators[crypto.Uint256](func(...dbft.Transaction[crypto.Uint256]) []dbft.PublicKey { return s.pubs }),
-		dbft.WithKeyPair[crypto.Uint256](s.privs[s.myIndex], s.pubs[s.myIndex]),
+		dbft.WithGetKeyPair[crypto.Uint256](func(_ []dbft.PublicKey) (int, dbft.PrivateKey, dbft.PublicKey) {
+			return s.myIndex, s.privs[s.myIndex], s.pubs[s.myIndex]
+		}),
 		dbft.WithBroadcast[crypto.Uint256](func(p Payload) { s.ch = append(s.ch, p) }),
 		dbft.WithGetTx[crypto.Uint256](s.pool.Get),
 		dbft.WithProcessBlock[crypto.Uint256](func(b dbft.Block[crypto.Uint256]) { s.blocks = append(s.blocks, b) }),
diff --git a/identity.go b/identity.go
index 8ab67b81..9b41e952 100644
--- a/identity.go
+++ b/identity.go
@@ -1,19 +1,12 @@
 package dbft
 
 import (
-	"encoding"
 	"fmt"
 )
 
 type (
 	// PublicKey is a generic public key interface used by dbft.
-	PublicKey interface {
-		encoding.BinaryMarshaler
-		encoding.BinaryUnmarshaler
-
-		// Verify verifies if sig is indeed msg's signature.
-		Verify(msg, sig []byte) error
-	}
+	PublicKey any
 
 	// PrivateKey is a generic private key interface used by dbft.
 	PrivateKey interface {
diff --git a/internal/consensus/block.go b/internal/consensus/block.go
index b24d7ccb..81a7fbe3 100644
--- a/internal/consensus/block.go
+++ b/internal/consensus/block.go
@@ -114,7 +114,7 @@ func (b *neoBlock) Sign(key dbft.PrivateKey) error {
 // Verify implements Block interface.
 func (b *neoBlock) Verify(pub dbft.PublicKey, sign []byte) error {
 	data := b.GetHashData()
-	return pub.Verify(data, sign)
+	return pub.(*crypto.ECDSAPub).Verify(data, sign)
 }
 
 // Hash implements Block interface.
diff --git a/internal/consensus/consensus.go b/internal/consensus/consensus.go
index e264d884..c4cd7b69 100644
--- a/internal/consensus/consensus.go
+++ b/internal/consensus/consensus.go
@@ -22,7 +22,15 @@ func New(logger *zap.Logger, key dbft.PrivateKey, pub dbft.PublicKey,
 		dbft.WithTimer[crypto.Uint256](timer.New()),
 		dbft.WithLogger[crypto.Uint256](logger),
 		dbft.WithSecondsPerBlock[crypto.Uint256](time.Second*5),
-		dbft.WithKeyPair[crypto.Uint256](key, pub),
+		dbft.WithGetKeyPair[crypto.Uint256](func(pubs []dbft.PublicKey) (int, dbft.PrivateKey, dbft.PublicKey) {
+			for i := range pubs {
+				if pub.(*crypto.ECDSAPub).Equals(pubs[i]) {
+					return i, key, pub
+				}
+			}
+
+			return -1, nil, nil
+		}),
 		dbft.WithGetTx[crypto.Uint256](getTx),
 		dbft.WithGetVerified[crypto.Uint256](getVerified),
 		dbft.WithBroadcast[crypto.Uint256](broadcast),
diff --git a/internal/crypto/crypto_test.go b/internal/crypto/crypto_test.go
index 52ca81dc..9655e001 100644
--- a/internal/crypto/crypto_test.go
+++ b/internal/crypto/crypto_test.go
@@ -19,7 +19,7 @@ func TestVerifySignature(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, 64, len(sign))
 
-	err = pub.Verify(data, sign)
+	err = pub.(*ECDSAPub).Verify(data, sign)
 	require.NoError(t, err)
 }
 
diff --git a/internal/crypto/ecdsa.go b/internal/crypto/ecdsa.go
index 275221c0..85c4cf04 100644
--- a/internal/crypto/ecdsa.go
+++ b/internal/crypto/ecdsa.go
@@ -62,6 +62,11 @@ func (e ECDSAPriv) Sign(msg []byte) ([]byte, error) {
 	return sig, nil
 }
 
+// Equals implements dbft.PublicKey interface.
+func (e *ECDSAPub) Equals(other dbft.PublicKey) bool {
+	return e.Equal(other.(*ECDSAPub).PublicKey)
+}
+
 // MarshalBinary implements encoding.BinaryMarshaler interface.
 func (e ECDSAPub) MarshalBinary() ([]byte, error) {
 	return elliptic.MarshalCompressed(e.PublicKey.Curve, e.PublicKey.X, e.PublicKey.Y), nil
diff --git a/internal/crypto/ecdsa_test.go b/internal/crypto/ecdsa_test.go
index 5623716f..d792cdb6 100644
--- a/internal/crypto/ecdsa_test.go
+++ b/internal/crypto/ecdsa_test.go
@@ -13,7 +13,7 @@ func TestECDSA_MarshalUnmarshal(t *testing.T) {
 	require.NotNil(t, priv)
 	require.NotNil(t, pub)
 
-	data, err := pub.MarshalBinary()
+	data, err := pub.(*ECDSAPub).MarshalBinary()
 	require.NoError(t, err)
 
 	pub1 := new(ECDSAPub)
diff --git a/internal/simulation/main.go b/internal/simulation/main.go
index 4587b358..5c42aa09 100644
--- a/internal/simulation/main.go
+++ b/internal/simulation/main.go
@@ -155,8 +155,8 @@ func updatePublicKeys(nodes []*simNode, n int) {
 
 func sortValidators(pubs []dbft.PublicKey) {
 	sort.Slice(pubs, func(i, j int) bool {
-		p1, _ := pubs[i].MarshalBinary()
-		p2, _ := pubs[j].MarshalBinary()
+		p1, _ := pubs[i].(*crypto.ECDSAPub).MarshalBinary()
+		p2, _ := pubs[j].(*crypto.ECDSAPub).MarshalBinary()
 		return murmur3.Sum64(p1) < murmur3.Sum64(p2)
 	})
 }