diff --git a/Makefile b/Makefile
index 6609e486..ed43e588 100644
--- a/Makefile
+++ b/Makefile
@@ -109,3 +109,12 @@ help:
 # Clean up
 clean:
 	rm -rf $(BINDIR)
+
+protoc:
+	# Protoc generate
+	@for f in `find . -type f -name '*.proto' -not -path './vendor/*'`; do \
+		echo "⇒ Processing $$f "; \
+		protoc \
+			--go_out=paths=source_relative:. $$f; \
+	done
+	rm -rf vendor
diff --git a/creds/accessbox/accessbox.pb.go b/creds/accessbox/accessbox.pb.go
new file mode 100644
index 00000000..b457d8ee
--- /dev/null
+++ b/creds/accessbox/accessbox.pb.go
@@ -0,0 +1,250 @@
+// Code generated by protoc-gen-go. DO NOT EDIT.
+// versions:
+// 	protoc-gen-go v1.25.0
+// 	protoc        v3.15.8
+// source: creds/accessbox/accessbox.proto
+
+package accessbox
+
+import (
+	proto "github.com/golang/protobuf/proto"
+	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
+	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
+	reflect "reflect"
+	sync "sync"
+)
+
+const (
+	// Verify that this generated code is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion)
+	// Verify that runtime/protoimpl is sufficiently up-to-date.
+	_ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20)
+)
+
+// This is a compile-time assertion that a sufficiently up-to-date version
+// of the legacy proto package is being used.
+const _ = proto.ProtoPackageIsVersion4
+
+type AccessBox struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	OwnerPublicKey []byte             `protobuf:"bytes,1,opt,name=ownerPublicKey,json=oownerPublicKey,proto3" json:"ownerPublicKey,omitempty"`
+	BearerTokens   []*AccessBox_Token `protobuf:"bytes,2,rep,name=bearerTokens,proto3" json:"bearerTokens,omitempty"`
+	SessionTokens  []*AccessBox_Token `protobuf:"bytes,3,rep,name=sessionTokens,proto3" json:"sessionTokens,omitempty"`
+}
+
+func (x *AccessBox) Reset() {
+	*x = AccessBox{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_creds_accessbox_accessbox_proto_msgTypes[0]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *AccessBox) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*AccessBox) ProtoMessage() {}
+
+func (x *AccessBox) ProtoReflect() protoreflect.Message {
+	mi := &file_creds_accessbox_accessbox_proto_msgTypes[0]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use AccessBox.ProtoReflect.Descriptor instead.
+func (*AccessBox) Descriptor() ([]byte, []int) {
+	return file_creds_accessbox_accessbox_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *AccessBox) GetOwnerPublicKey() []byte {
+	if x != nil {
+		return x.OwnerPublicKey
+	}
+	return nil
+}
+
+func (x *AccessBox) GetBearerTokens() []*AccessBox_Token {
+	if x != nil {
+		return x.BearerTokens
+	}
+	return nil
+}
+
+func (x *AccessBox) GetSessionTokens() []*AccessBox_Token {
+	if x != nil {
+		return x.SessionTokens
+	}
+	return nil
+}
+
+type AccessBox_Token struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	Token         []byte `protobuf:"bytes,1,opt,name=token,proto3" json:"token,omitempty"`
+	GatePublicKey []byte `protobuf:"bytes,2,opt,name=gatePublicKey,proto3" json:"gatePublicKey,omitempty"`
+}
+
+func (x *AccessBox_Token) Reset() {
+	*x = AccessBox_Token{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_creds_accessbox_accessbox_proto_msgTypes[1]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *AccessBox_Token) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*AccessBox_Token) ProtoMessage() {}
+
+func (x *AccessBox_Token) ProtoReflect() protoreflect.Message {
+	mi := &file_creds_accessbox_accessbox_proto_msgTypes[1]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use AccessBox_Token.ProtoReflect.Descriptor instead.
+func (*AccessBox_Token) Descriptor() ([]byte, []int) {
+	return file_creds_accessbox_accessbox_proto_rawDescGZIP(), []int{0, 0}
+}
+
+func (x *AccessBox_Token) GetToken() []byte {
+	if x != nil {
+		return x.Token
+	}
+	return nil
+}
+
+func (x *AccessBox_Token) GetGatePublicKey() []byte {
+	if x != nil {
+		return x.GatePublicKey
+	}
+	return nil
+}
+
+var File_creds_accessbox_accessbox_proto protoreflect.FileDescriptor
+
+var file_creds_accessbox_accessbox_proto_rawDesc = []byte{
+	0x0a, 0x1f, 0x63, 0x72, 0x65, 0x64, 0x73, 0x2f, 0x61, 0x63, 0x63, 0x65, 0x73, 0x73, 0x62, 0x6f,
+	0x78, 0x2f, 0x61, 0x63, 0x63, 0x65, 0x73, 0x73, 0x62, 0x6f, 0x78, 0x2e, 0x70, 0x72, 0x6f, 0x74,
+	0x6f, 0x12, 0x09, 0x61, 0x63, 0x63, 0x65, 0x73, 0x73, 0x62, 0x6f, 0x78, 0x22, 0xfb, 0x01, 0x0a,
+	0x09, 0x41, 0x63, 0x63, 0x65, 0x73, 0x73, 0x42, 0x6f, 0x78, 0x12, 0x27, 0x0a, 0x0e, 0x6f, 0x77,
+	0x6e, 0x65, 0x72, 0x50, 0x75, 0x62, 0x6c, 0x69, 0x63, 0x4b, 0x65, 0x79, 0x18, 0x01, 0x20, 0x01,
+	0x28, 0x0c, 0x52, 0x0f, 0x6f, 0x6f, 0x77, 0x6e, 0x65, 0x72, 0x50, 0x75, 0x62, 0x6c, 0x69, 0x63,
+	0x4b, 0x65, 0x79, 0x12, 0x3e, 0x0a, 0x0c, 0x62, 0x65, 0x61, 0x72, 0x65, 0x72, 0x54, 0x6f, 0x6b,
+	0x65, 0x6e, 0x73, 0x18, 0x02, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x1a, 0x2e, 0x61, 0x63, 0x63, 0x65,
+	0x73, 0x73, 0x62, 0x6f, 0x78, 0x2e, 0x41, 0x63, 0x63, 0x65, 0x73, 0x73, 0x42, 0x6f, 0x78, 0x2e,
+	0x54, 0x6f, 0x6b, 0x65, 0x6e, 0x52, 0x0c, 0x62, 0x65, 0x61, 0x72, 0x65, 0x72, 0x54, 0x6f, 0x6b,
+	0x65, 0x6e, 0x73, 0x12, 0x40, 0x0a, 0x0d, 0x73, 0x65, 0x73, 0x73, 0x69, 0x6f, 0x6e, 0x54, 0x6f,
+	0x6b, 0x65, 0x6e, 0x73, 0x18, 0x03, 0x20, 0x03, 0x28, 0x0b, 0x32, 0x1a, 0x2e, 0x61, 0x63, 0x63,
+	0x65, 0x73, 0x73, 0x62, 0x6f, 0x78, 0x2e, 0x41, 0x63, 0x63, 0x65, 0x73, 0x73, 0x42, 0x6f, 0x78,
+	0x2e, 0x54, 0x6f, 0x6b, 0x65, 0x6e, 0x52, 0x0d, 0x73, 0x65, 0x73, 0x73, 0x69, 0x6f, 0x6e, 0x54,
+	0x6f, 0x6b, 0x65, 0x6e, 0x73, 0x1a, 0x43, 0x0a, 0x05, 0x54, 0x6f, 0x6b, 0x65, 0x6e, 0x12, 0x14,
+	0x0a, 0x05, 0x74, 0x6f, 0x6b, 0x65, 0x6e, 0x18, 0x01, 0x20, 0x01, 0x28, 0x0c, 0x52, 0x05, 0x74,
+	0x6f, 0x6b, 0x65, 0x6e, 0x12, 0x24, 0x0a, 0x0d, 0x67, 0x61, 0x74, 0x65, 0x50, 0x75, 0x62, 0x6c,
+	0x69, 0x63, 0x4b, 0x65, 0x79, 0x18, 0x02, 0x20, 0x01, 0x28, 0x0c, 0x52, 0x0d, 0x67, 0x61, 0x74,
+	0x65, 0x50, 0x75, 0x62, 0x6c, 0x69, 0x63, 0x4b, 0x65, 0x79, 0x42, 0x3b, 0x5a, 0x39, 0x67, 0x69,
+	0x74, 0x68, 0x75, 0x62, 0x2e, 0x63, 0x6f, 0x6d, 0x2f, 0x6e, 0x73, 0x70, 0x63, 0x63, 0x2d, 0x64,
+	0x65, 0x76, 0x2f, 0x6e, 0x65, 0x6f, 0x66, 0x73, 0x2d, 0x73, 0x33, 0x2d, 0x67, 0x77, 0x2f, 0x63,
+	0x72, 0x65, 0x64, 0x73, 0x2f, 0x74, 0x6f, 0x6b, 0x65, 0x6e, 0x62, 0x6f, 0x78, 0x3b, 0x61, 0x63,
+	0x63, 0x65, 0x73, 0x73, 0x62, 0x6f, 0x78, 0x62, 0x06, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x33,
+}
+
+var (
+	file_creds_accessbox_accessbox_proto_rawDescOnce sync.Once
+	file_creds_accessbox_accessbox_proto_rawDescData = file_creds_accessbox_accessbox_proto_rawDesc
+)
+
+func file_creds_accessbox_accessbox_proto_rawDescGZIP() []byte {
+	file_creds_accessbox_accessbox_proto_rawDescOnce.Do(func() {
+		file_creds_accessbox_accessbox_proto_rawDescData = protoimpl.X.CompressGZIP(file_creds_accessbox_accessbox_proto_rawDescData)
+	})
+	return file_creds_accessbox_accessbox_proto_rawDescData
+}
+
+var file_creds_accessbox_accessbox_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
+var file_creds_accessbox_accessbox_proto_goTypes = []interface{}{
+	(*AccessBox)(nil),       // 0: accessbox.AccessBox
+	(*AccessBox_Token)(nil), // 1: accessbox.AccessBox.Token
+}
+var file_creds_accessbox_accessbox_proto_depIdxs = []int32{
+	1, // 0: accessbox.AccessBox.bearerTokens:type_name -> accessbox.AccessBox.Token
+	1, // 1: accessbox.AccessBox.sessionTokens:type_name -> accessbox.AccessBox.Token
+	2, // [2:2] is the sub-list for method output_type
+	2, // [2:2] is the sub-list for method input_type
+	2, // [2:2] is the sub-list for extension type_name
+	2, // [2:2] is the sub-list for extension extendee
+	0, // [0:2] is the sub-list for field type_name
+}
+
+func init() { file_creds_accessbox_accessbox_proto_init() }
+func file_creds_accessbox_accessbox_proto_init() {
+	if File_creds_accessbox_accessbox_proto != nil {
+		return
+	}
+	if !protoimpl.UnsafeEnabled {
+		file_creds_accessbox_accessbox_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*AccessBox); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_creds_accessbox_accessbox_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*AccessBox_Token); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+	}
+	type x struct{}
+	out := protoimpl.TypeBuilder{
+		File: protoimpl.DescBuilder{
+			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
+			RawDescriptor: file_creds_accessbox_accessbox_proto_rawDesc,
+			NumEnums:      0,
+			NumMessages:   2,
+			NumExtensions: 0,
+			NumServices:   0,
+		},
+		GoTypes:           file_creds_accessbox_accessbox_proto_goTypes,
+		DependencyIndexes: file_creds_accessbox_accessbox_proto_depIdxs,
+		MessageInfos:      file_creds_accessbox_accessbox_proto_msgTypes,
+	}.Build()
+	File_creds_accessbox_accessbox_proto = out.File
+	file_creds_accessbox_accessbox_proto_rawDesc = nil
+	file_creds_accessbox_accessbox_proto_goTypes = nil
+	file_creds_accessbox_accessbox_proto_depIdxs = nil
+}
diff --git a/creds/accessbox/accessbox.proto b/creds/accessbox/accessbox.proto
new file mode 100644
index 00000000..8906c926
--- /dev/null
+++ b/creds/accessbox/accessbox.proto
@@ -0,0 +1,19 @@
+syntax = "proto3";
+
+package accessbox;
+
+option go_package = "github.com/nspcc-dev/neofs-s3-gw/creds/tokenbox;accessbox";
+
+
+
+message AccessBox {
+    message Token {
+        bytes token = 1 [json_name = "token"];
+        bytes gatePublicKey = 2 [json_name = "gatePublicKey"];
+    }
+
+    bytes ownerPublicKey = 1 [json_name = "oownerPublicKey"];
+    repeated Token bearerTokens = 2 [json_name = "bearerTokens"];
+    repeated Token sessionTokens = 3 [json_name = "sessionTokens"];
+}
+
diff --git a/go.mod b/go.mod
index 2f1ee8eb..7896b055 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,7 @@ go 1.16
 
 require (
 	github.com/aws/aws-sdk-go v1.37.9
+	github.com/golang/protobuf v1.4.3
 	github.com/google/uuid v1.2.0
 	github.com/gorilla/mux v1.8.0
 	github.com/nspcc-dev/neofs-api-go v1.27.0
@@ -21,4 +22,5 @@ require (
 	golang.org/x/sys v0.0.0-20210225134936-a50acf3fe073 // indirect
 	golang.org/x/text v0.3.5 // indirect
 	google.golang.org/grpc v1.36.1
+	google.golang.org/protobuf v1.25.0
 )