diff --git a/blockchain/abci.go b/blockchain/abci.go
index 1c4bb86..8da06af 100644
--- a/blockchain/abci.go
+++ b/blockchain/abci.go
@@ -1,7 +1,10 @@
 package blockchain
 
 import (
+	"crypto/ed25519"
+	"encoding/base64"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strings"
 
@@ -14,10 +17,172 @@ type PromiseApp struct {
 	currentBatch *badger.Txn
 }
 
+type CommiterTxBody struct {
+	Type           string `json:"type"`
+	ID             string `json:"id"`
+	Name           string `json:"name"`
+	CommiterPubKey string `json:"commiter_pubkey"`
+}
+
+type PromiseTxBody struct {
+	Type        string `json:"type"`
+	ID          string `json:"id"`
+	Description string `json:"description"`
+	Timestamp   int64  `json:"timestamp,omitempty"` // ← чтобы понимать клиент
+	Title       string `json:"title,omitempty"`     // ← опционально, если когда-нибудь пригодится
+	Deadline    string `json:"deadline,omitempty"`
+}
+
+type CommitmentTxBody struct {
+	Type        string `json:"type"`
+	ID          string `json:"id"`
+	PromiseID   string `json:"promise_id"`
+	CommiterID  string `json:"commiter_id"`
+	CommiterSig string `json:"commiter_sig,omitempty"`
+}
+
+type compoundTxRaw struct {
+	Body      json.RawMessage `json:"body"`
+	Signature string          `json:"signature"`
+}
+
+type compoundBody struct {
+	Promise    *PromiseTxBody    `json:"promise"`
+	Commitment *CommitmentTxBody `json:"commitment"`
+}
+
+type CompoundTx struct {
+	Body struct {
+		Promise    *PromiseTxBody    `json:"promise"`
+		Commitment *CommitmentTxBody `json:"commitment"`
+	} `json:"body"`
+	Signature string `json:"signature"`
+}
+
 func NewPromiseApp(db *badger.DB) *PromiseApp {
 	return &PromiseApp{db: db}
 }
 
+func verifyAndExtractBody(db *badger.DB, tx []byte) (map[string]interface{}, error) {
+	var outer struct {
+		Body      CommiterTxBody `json:"body"`
+		Signature string         `json:"signature"`
+	}
+
+	if err := json.Unmarshal(tx, &outer); err != nil {
+		return nil, errors.New("invalid JSON wrapper")
+	}
+
+	msg, err := json.Marshal(outer.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	sig, err := base64.StdEncoding.DecodeString(outer.Signature)
+	if err != nil {
+		return nil, errors.New("invalid signature base64")
+	}
+	if len(sig) != ed25519.SignatureSize {
+		return nil, fmt.Errorf("invalid signature length: got %d, want %d", len(sig), ed25519.SignatureSize)
+	}
+
+	pubkeyB64 := strings.TrimSpace(outer.Body.CommiterPubKey)
+	if pubkeyB64 == "" {
+		return nil, errors.New("missing commiter pubkey")
+	}
+	pubkey, err := base64.StdEncoding.DecodeString(pubkeyB64)
+	if err != nil {
+		return nil, errors.New("invalid pubkey base64")
+	}
+	if len(pubkey) != ed25519.PublicKeySize {
+		return nil, fmt.Errorf("invalid pubkey length: got %d, want %d", len(pubkey), ed25519.PublicKeySize)
+	}
+
+	if !ed25519.Verify(pubkey, msg, sig) {
+		return nil, errors.New("signature verification failed")
+	}
+
+	var result map[string]interface{}
+	if err := json.Unmarshal(msg, &result); err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}
+
+func (app *PromiseApp) CheckTx(req abci.RequestCheckTx) abci.ResponseCheckTx {
+	compound, err := verifyCompoundTx(app.db, req.Tx)
+	if err == nil {
+		// Проверка на уникальность Promise.ID
+		if compound.Body.Promise != nil {
+			err := app.db.View(func(txn *badger.Txn) error {
+				_, err := txn.Get([]byte(compound.Body.Promise.ID))
+				if err == badger.ErrKeyNotFound {
+					return nil
+				}
+				return errors.New("duplicate promise ID")
+			})
+			if err != nil {
+				return abci.ResponseCheckTx{Code: 2, Log: err.Error()}
+			}
+		}
+
+		// Проверка на уникальность Commitment.ID
+		if compound.Body.Commitment != nil {
+			err := app.db.View(func(txn *badger.Txn) error {
+				_, err := txn.Get([]byte(compound.Body.Commitment.ID))
+				if err == badger.ErrKeyNotFound {
+					return nil
+				}
+				return errors.New("duplicate commitment ID")
+			})
+			if err != nil {
+				return abci.ResponseCheckTx{Code: 3, Log: err.Error()}
+			}
+		}
+
+		// Проверка на существование коммитера
+		if compound.Body.Commitment != nil {
+			err := app.db.View(func(txn *badger.Txn) error {
+				_, err := txn.Get([]byte(compound.Body.Commitment.CommiterID))
+				if err == badger.ErrKeyNotFound {
+					return errors.New("unknown commiter")
+				}
+				return nil
+			})
+			if err != nil {
+				return abci.ResponseCheckTx{Code: 4, Log: err.Error()}
+			}
+		}
+
+		return abci.ResponseCheckTx{Code: 0}
+	}
+
+	// Попытка старого формата только если он реально валиден;
+	// иначе возвращаем исходную причину из verifyCompoundTx.
+	if body, oldErr := verifyAndExtractBody(app.db, req.Tx); oldErr == nil {
+		id, ok := body["id"].(string)
+		if !ok || id == "" {
+			return abci.ResponseCheckTx{Code: 2, Log: "missing id"}
+		}
+		// Проверка на дубликат
+		err := app.db.View(func(txn *badger.Txn) error {
+			_, err := txn.Get([]byte(id))
+			if err == badger.ErrKeyNotFound {
+				return nil
+			}
+			return errors.New("duplicate id")
+		})
+		if err != nil {
+			return abci.ResponseCheckTx{Code: 3, Log: err.Error()}
+		}
+		return abci.ResponseCheckTx{Code: 0}
+	}
+
+	// Здесь: составной формат не прошёл — вернём ПРИЧИНУ.
+	return abci.ResponseCheckTx{Code: 1, Log: err.Error()}
+}
+
 func (app *PromiseApp) BeginBlock(_ abci.RequestBeginBlock) abci.ResponseBeginBlock {
 	if app.currentBatch != nil {
 		app.currentBatch.Discard()
@@ -27,52 +192,145 @@ func (app *PromiseApp) BeginBlock(_ abci.RequestBeginBlock) abci.ResponseBeginBl
 }
 
 func (app *PromiseApp) DeliverTx(req abci.RequestDeliverTx) abci.ResponseDeliverTx {
-	var tx map[string]interface{}
-	if err := json.Unmarshal(req.Tx, &tx); err != nil {
-		return abci.ResponseDeliverTx{Code: 1, Log: "invalid JSON"}
-	}
+	compound, err := verifyCompoundTx(app.db, req.Tx)
+	if err != nil {
+		outer := struct {
+			Body      CommiterTxBody `json:"body"`
+			Signature string         `json:"signature"`
+		}{}
+		if err := json.Unmarshal(req.Tx, &outer); err != nil {
+			return abci.ResponseDeliverTx{Code: 1, Log: "invalid tx format"}
+		}
+		// Валидация подписи/ключа одиночного коммитера перед записью
+		if _, vErr := verifyAndExtractBody(app.db, req.Tx); vErr != nil {
+			return abci.ResponseDeliverTx{Code: 1, Log: vErr.Error()}
+		}
 
-	id, ok := tx["id"].(string)
-	if !ok || id == "" {
-		return abci.ResponseDeliverTx{Code: 2, Log: "missing id"}
-	}
+		id := outer.Body.ID
+		if id == "" {
+			return abci.ResponseDeliverTx{Code: 1, Log: "missing id"}
+		}
 
-	data, _ := json.Marshal(tx)
+		if app.currentBatch == nil {
+			app.currentBatch = app.db.NewTransaction(true)
+		}
+
+		data, err := json.Marshal(outer.Body)
+		if err != nil {
+			return abci.ResponseDeliverTx{Code: 1, Log: err.Error()}
+		}
+		if err = app.currentBatch.Set([]byte(id), data); err != nil {
+			return abci.ResponseDeliverTx{Code: 1, Log: err.Error()}
+		}
+		return abci.ResponseDeliverTx{Code: 0}
+	}
 
 	if app.currentBatch == nil {
 		app.currentBatch = app.db.NewTransaction(true)
 	}
-	err := app.currentBatch.Set([]byte(id), data)
-	if err != nil {
-		return abci.ResponseDeliverTx{Code: 1, Log: fmt.Sprintf("failed to set: %v", err)}
+
+	if compound.Body.Promise != nil {
+		data, _ := json.Marshal(compound.Body.Promise)
+		err := app.currentBatch.Set([]byte(compound.Body.Promise.ID), data)
+		if err != nil {
+			return abci.ResponseDeliverTx{Code: 1, Log: "failed to save promise"}
+		}
+	}
+	if compound.Body.Commitment != nil {
+		data, _ := json.Marshal(compound.Body.Commitment)
+		err := app.currentBatch.Set([]byte(compound.Body.Commitment.ID), data)
+		if err != nil {
+			return abci.ResponseDeliverTx{Code: 1, Log: "failed to save commitment"}
+		}
 	}
 
 	return abci.ResponseDeliverTx{Code: 0}
 }
 
-func (app *PromiseApp) CheckTx(req abci.RequestCheckTx) abci.ResponseCheckTx {
-	var tx map[string]interface{}
-	if err := json.Unmarshal(req.Tx, &tx); err != nil {
-		return abci.ResponseCheckTx{Code: 1, Log: "invalid JSON"}
+func verifyCompoundTx(db *badger.DB, tx []byte) (*CompoundTx, error) {
+	// 1) Разобрать внешний конверт, body оставить сырым
+	var outerRaw compoundTxRaw
+	if err := json.Unmarshal(tx, &outerRaw); err != nil {
+		return nil, errors.New("invalid compound tx JSON")
 	}
-	id, ok := tx["id"].(string)
-	if !ok || id == "" {
-		return abci.ResponseCheckTx{Code: 2, Log: "missing id"}
+	if len(outerRaw.Body) == 0 {
+		return nil, errors.New("missing body")
 	}
 
-	// проверка уникальности id
-	err := app.db.View(func(txn *badger.Txn) error {
-		_, err := txn.Get([]byte(id))
-		if err == badger.ErrKeyNotFound {
-			return nil
+	// 2) Вынуть commiter_id из body, не парся всё
+	var tiny struct {
+		Commitment *struct {
+			CommiterID string `json:"commiter_id"`
+		} `json:"commitment"`
+	}
+	if err := json.Unmarshal(outerRaw.Body, &tiny); err != nil {
+		return nil, errors.New("invalid body JSON")
+	}
+	if tiny.Commitment == nil || strings.TrimSpace(tiny.Commitment.CommiterID) == "" {
+		return nil, errors.New("missing commitment")
+	}
+	commiterID := tiny.Commitment.CommiterID
+
+	// 3) Достать коммитера из БД и получить публичный ключ
+	var commiterData []byte
+	err := db.View(func(txn *badger.Txn) error {
+		item, err := txn.Get([]byte(commiterID))
+		if err != nil {
+			return errors.New("unknown commiter")
 		}
-		return fmt.Errorf("id exists")
+		return item.Value(func(v []byte) error {
+			commiterData = append([]byte{}, v...)
+			return nil
+		})
 	})
 	if err != nil {
-		return abci.ResponseCheckTx{Code: 3, Log: "duplicate id"}
+		return nil, err
+	}
+	var commiter CommiterTxBody
+	if err := json.Unmarshal(commiterData, &commiter); err != nil {
+		return nil, errors.New("corrupted commiter record")
+	}
+	pubkeyB64 := strings.TrimSpace(commiter.CommiterPubKey)
+	if pubkeyB64 == "" {
+		return nil, errors.New("missing commiter pubkey")
+	}
+	pubkey, err := base64.StdEncoding.DecodeString(pubkeyB64)
+	if err != nil {
+		return nil, errors.New("invalid pubkey base64")
+	}
+	if len(pubkey) != ed25519.PublicKeySize {
+		return nil, fmt.Errorf("invalid pubkey length: got %d, want %d", len(pubkey), ed25519.PublicKeySize)
 	}
 
-	return abci.ResponseCheckTx{Code: 0}
+	// 4) Проверка подписи над СЫРЫМИ БАЙТАМИ body (как клиент подписывал)
+	sig, err := base64.StdEncoding.DecodeString(outerRaw.Signature)
+	if err != nil {
+		return nil, errors.New("invalid signature base64")
+	}
+	if len(sig) != ed25519.SignatureSize {
+		return nil, fmt.Errorf("invalid signature length: got %d, want %d", len(sig), ed25519.SignatureSize)
+	}
+	if !ed25519.Verify(pubkey, outerRaw.Body, sig) {
+		return nil, errors.New("signature verification failed")
+	}
+
+	// 5) Только после успешной проверки — распарсить body в наши структуры
+	var body compoundBody
+	if err := json.Unmarshal(outerRaw.Body, &body); err != nil {
+		return nil, errors.New("invalid body JSON")
+	}
+
+	// 6) Вернуть в привычной форме
+	return &CompoundTx{
+		Body: struct {
+			Promise    *PromiseTxBody    `json:"promise"`
+			Commitment *CommitmentTxBody `json:"commitment"`
+		}{
+			Promise:    body.Promise,
+			Commitment: body.Commitment,
+		},
+		Signature: outerRaw.Signature,
+	}, nil
 }
 
 func (app *PromiseApp) Commit() abci.ResponseCommit {
@@ -86,7 +344,6 @@ func (app *PromiseApp) Commit() abci.ResponseCommit {
 	return abci.ResponseCommit{Data: []byte{}}
 }
 
-// SELECT * FROM <table>
 func (app *PromiseApp) Query(req abci.RequestQuery) abci.ResponseQuery {
 	parts := strings.Split(strings.Trim(req.Path, "/"), "/")
 	if len(parts) != 2 || parts[0] != "list" {
@@ -98,7 +355,6 @@ func (app *PromiseApp) Query(req abci.RequestQuery) abci.ResponseQuery {
 	err := app.db.View(func(txn *badger.Txn) error {
 		it := txn.NewIterator(badger.DefaultIteratorOptions)
 		defer it.Close()
-
 		for it.Seek(prefix); it.ValidForPrefix(prefix); it.Next() {
 			item := it.Item()
 			err := item.Value(func(v []byte) error {
@@ -117,12 +373,10 @@ func (app *PromiseApp) Query(req abci.RequestQuery) abci.ResponseQuery {
 	if err != nil {
 		return abci.ResponseQuery{Code: 1, Log: err.Error()}
 	}
-
 	all, _ := json.Marshal(result)
 	return abci.ResponseQuery{Code: 0, Value: all}
 }
 
-// Остальные методы ABCI
 func (app *PromiseApp) Info(req abci.RequestInfo) abci.ResponseInfo {
 	return abci.ResponseInfo{Data: "promises", Version: "0.1"}
 }