diff --git a/native/cpp/CommonCpp/CryptoTools/CryptoModule.cpp b/native/cpp/CommonCpp/CryptoTools/CryptoModule.cpp
--- a/native/cpp/CommonCpp/CryptoTools/CryptoModule.cpp
+++ b/native/cpp/CommonCpp/CryptoTools/CryptoModule.cpp
@@ -383,26 +383,7 @@
   if (!this->hasSessionFor(targetDeviceId)) {
     throw std::runtime_error{"error encrypt => uninitialized session"};
   }
-  OlmSession *session = this->sessions.at(targetDeviceId)->getOlmSession();
-  OlmBuffer encryptedMessage(
-      ::olm_encrypt_message_length(session, content.size()));
-  OlmBuffer messageRandom;
-  PlatformSpecificTools::generateSecureRandomBytes(
-      messageRandom, ::olm_encrypt_random_length(session));
-  size_t messageType = ::olm_encrypt_message_type(session);
-  if (-1 ==
-      ::olm_encrypt(
-          session,
-          (uint8_t *)content.data(),
-          content.size(),
-          messageRandom.data(),
-          messageRandom.size(),
-          encryptedMessage.data(),
-          encryptedMessage.size())) {
-    throw std::runtime_error{
-        "error encrypt => " + std::string{::olm_session_last_error(session)}};
-  }
-  return {encryptedMessage, messageType};
+  return this->sessions.at(targetDeviceId)->encrypt(content);
 }
 
 std::string CryptoModule::decrypt(
diff --git a/native/cpp/CommonCpp/CryptoTools/Session.h b/native/cpp/CommonCpp/CryptoTools/Session.h
--- a/native/cpp/CommonCpp/CryptoTools/Session.h
+++ b/native/cpp/CommonCpp/CryptoTools/Session.h
@@ -33,6 +33,7 @@
   restoreFromB64(const std::string &secretKey, OlmBuffer &b64);
   OlmSession *getOlmSession();
   std::string decrypt(EncryptedData &encryptedData);
+  EncryptedData encrypt(const std::string &content);
   std::string decryptSequential(EncryptedData &encryptedData);
   int getVersion();
   void setVersion(int newVersion);
diff --git a/native/cpp/CommonCpp/CryptoTools/Session.cpp b/native/cpp/CommonCpp/CryptoTools/Session.cpp
--- a/native/cpp/CommonCpp/CryptoTools/Session.cpp
+++ b/native/cpp/CommonCpp/CryptoTools/Session.cpp
@@ -179,6 +179,29 @@
   return std::string{(char *)decryptedMessage.data(), decryptedSize};
 }
 
+EncryptedData Session::encrypt(const std::string &content) {
+  OlmSession *session = this->getOlmSession();
+  OlmBuffer encryptedMessage(
+      ::olm_encrypt_message_length(session, content.size()));
+  OlmBuffer messageRandom;
+  PlatformSpecificTools::generateSecureRandomBytes(
+      messageRandom, ::olm_encrypt_random_length(session));
+  size_t messageType = ::olm_encrypt_message_type(session);
+  if (-1 ==
+      ::olm_encrypt(
+          session,
+          (uint8_t *)content.data(),
+          content.size(),
+          messageRandom.data(),
+          messageRandom.size(),
+          encryptedMessage.data(),
+          encryptedMessage.size())) {
+    throw std::runtime_error{
+        "error encrypt => " + std::string{::olm_session_last_error(session)}};
+  }
+  return {encryptedMessage, messageType};
+}
+
 std::string Session::decryptSequential(EncryptedData &encryptedData) {
   OlmSession *session = this->getOlmSession();
 
diff --git a/native/cpp/CommonCpp/NativeModules/CommCoreModule.h b/native/cpp/CommonCpp/NativeModules/CommCoreModule.h
--- a/native/cpp/CommonCpp/NativeModules/CommCoreModule.h
+++ b/native/cpp/CommonCpp/NativeModules/CommCoreModule.h
@@ -138,7 +138,11 @@
       std::optional<jsi::String> oneTimeKey,
       jsi::String deviceID) override;
   virtual jsi::Value
-  encrypt(jsi::Runtime &rt, jsi::String message, jsi::String deviceID) override;
+  encrypt(jsi::Runtime &rt, jsi::String payload, jsi::String deviceID) override;
+  virtual jsi::Value encryptNotification(
+      jsi::Runtime &rt,
+      jsi::String payload,
+      jsi::String deviceID) override;
   virtual jsi::Value encryptAndPersist(
       jsi::Runtime &rt,
       jsi::String message,
diff --git a/native/cpp/CommonCpp/NativeModules/CommCoreModule.cpp b/native/cpp/CommonCpp/NativeModules/CommCoreModule.cpp
--- a/native/cpp/CommonCpp/NativeModules/CommCoreModule.cpp
+++ b/native/cpp/CommonCpp/NativeModules/CommCoreModule.cpp
@@ -1550,6 +1550,44 @@
       });
 }
 
+jsi::Value CommCoreModule::encryptNotification(
+    jsi::Runtime &rt,
+    jsi::String payload,
+    jsi::String deviceID) {
+  auto payloadCpp{payload.utf8(rt)};
+  auto deviceIDCpp{deviceID.utf8(rt)};
+
+  return createPromiseAsJSIValue(
+      rt, [=](jsi::Runtime &innerRt, std::shared_ptr<Promise> promise) {
+        taskType job = [=, &innerRt]() {
+          std::string error;
+          crypto::EncryptedData result;
+          try {
+            result = NotificationsCryptoModule::encryptNotification(
+                deviceIDCpp, payloadCpp);
+          } catch (const std::exception &e) {
+            error = e.what();
+          }
+
+          this->jsInvoker_->invokeAsync([=, &innerRt]() {
+            if (error.size()) {
+              promise->reject(error);
+              return;
+            }
+            auto encryptedDataJSI = jsi::Object(innerRt);
+            auto message =
+                std::string{result.message.begin(), result.message.end()};
+            auto messageJSI = jsi::String::createFromUtf8(innerRt, message);
+            encryptedDataJSI.setProperty(innerRt, "message", messageJSI);
+            encryptedDataJSI.setProperty(
+                innerRt, "messageType", static_cast<int>(result.messageType));
+            promise->resolve(std::move(encryptedDataJSI));
+          });
+        };
+        this->cryptoThread->scheduleTask(job);
+      });
+}
+
 jsi::Value CommCoreModule::encryptAndPersist(
     jsi::Runtime &rt,
     jsi::String message,
diff --git a/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.h b/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.h
--- a/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.h
+++ b/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.h
@@ -116,6 +116,9 @@
       const std::string &data,
       const size_t messageType);
 
+  static crypto::EncryptedData
+  encryptNotification(const std::string &deviceID, const std::string &payload);
+
   static void
   flushState(std::unique_ptr<BaseStatefulDecryptResult> statefulDecryptResult);
 };
diff --git a/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.cpp b/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.cpp
--- a/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.cpp
+++ b/native/cpp/CommonCpp/Notifications/BackgroundDataStorage/NotificationsCryptoModule.cpp
@@ -413,6 +413,24 @@
   return decryptedData;
 }
 
+crypto::EncryptedData NotificationsCryptoModule::encryptNotification(
+    const std::string &deviceID,
+    const std::string &payload) {
+  auto sessionWithPicklingKey =
+      NotificationsCryptoModule::fetchNotificationsSession(false, deviceID);
+  if (!sessionWithPicklingKey.has_value()) {
+    throw std::runtime_error(
+        "Session with deviceID: " + deviceID + " not initialized.");
+  }
+  std::unique_ptr<crypto::Session> session =
+      std::move(sessionWithPicklingKey.value().first);
+  std::string picklingKey = sessionWithPicklingKey.value().second;
+  crypto::EncryptedData encryptedData = session->encrypt(payload);
+  NotificationsCryptoModule::persistNotificationsSessionInternal(
+      false, deviceID, picklingKey, std::move(session));
+  return encryptedData;
+}
+
 std::unique_ptr<NotificationsCryptoModule::BaseStatefulDecryptResult>
 NotificationsCryptoModule::statefulDecrypt(
     const std::string &keyserverID,
diff --git a/native/cpp/CommonCpp/_generated/commJSI-generated.cpp b/native/cpp/CommonCpp/_generated/commJSI-generated.cpp
--- a/native/cpp/CommonCpp/_generated/commJSI-generated.cpp
+++ b/native/cpp/CommonCpp/_generated/commJSI-generated.cpp
@@ -90,6 +90,9 @@
 static jsi::Value __hostFunction_CommCoreModuleSchemaCxxSpecJSI_encrypt(jsi::Runtime &rt, TurboModule &turboModule, const jsi::Value* args, size_t count) {
   return static_cast<CommCoreModuleSchemaCxxSpecJSI *>(&turboModule)->encrypt(rt, args[0].asString(rt), args[1].asString(rt));
 }
+static jsi::Value __hostFunction_CommCoreModuleSchemaCxxSpecJSI_encryptNotification(jsi::Runtime &rt, TurboModule &turboModule, const jsi::Value* args, size_t count) {
+  return static_cast<CommCoreModuleSchemaCxxSpecJSI *>(&turboModule)->encryptNotification(rt, args[0].asString(rt), args[1].asString(rt));
+}
 static jsi::Value __hostFunction_CommCoreModuleSchemaCxxSpecJSI_encryptAndPersist(jsi::Runtime &rt, TurboModule &turboModule, const jsi::Value* args, size_t count) {
   return static_cast<CommCoreModuleSchemaCxxSpecJSI *>(&turboModule)->encryptAndPersist(rt, args[0].asString(rt), args[1].asString(rt), args[2].asString(rt));
 }
@@ -239,6 +242,7 @@
   methodMap_["initializeContentInboundSession"] = MethodMetadata {5, __hostFunction_CommCoreModuleSchemaCxxSpecJSI_initializeContentInboundSession};
   methodMap_["initializeNotificationsOutboundSession"] = MethodMetadata {5, __hostFunction_CommCoreModuleSchemaCxxSpecJSI_initializeNotificationsOutboundSession};
   methodMap_["encrypt"] = MethodMetadata {2, __hostFunction_CommCoreModuleSchemaCxxSpecJSI_encrypt};
+  methodMap_["encryptNotification"] = MethodMetadata {2, __hostFunction_CommCoreModuleSchemaCxxSpecJSI_encryptNotification};
   methodMap_["encryptAndPersist"] = MethodMetadata {3, __hostFunction_CommCoreModuleSchemaCxxSpecJSI_encryptAndPersist};
   methodMap_["decrypt"] = MethodMetadata {2, __hostFunction_CommCoreModuleSchemaCxxSpecJSI_decrypt};
   methodMap_["decryptSequentialAndPersist"] = MethodMetadata {3, __hostFunction_CommCoreModuleSchemaCxxSpecJSI_decryptSequentialAndPersist};
diff --git a/native/cpp/CommonCpp/_generated/commJSI.h b/native/cpp/CommonCpp/_generated/commJSI.h
--- a/native/cpp/CommonCpp/_generated/commJSI.h
+++ b/native/cpp/CommonCpp/_generated/commJSI.h
@@ -45,6 +45,7 @@
   virtual jsi::Value initializeContentInboundSession(jsi::Runtime &rt, jsi::String identityKeys, jsi::Object encryptedContent, jsi::String deviceID, double sessionVersion, bool overwrite) = 0;
   virtual jsi::Value initializeNotificationsOutboundSession(jsi::Runtime &rt, jsi::String identityKeys, jsi::String prekey, jsi::String prekeySignature, std::optional<jsi::String> oneTimeKey, jsi::String deviceID) = 0;
   virtual jsi::Value encrypt(jsi::Runtime &rt, jsi::String message, jsi::String deviceID) = 0;
+  virtual jsi::Value encryptNotification(jsi::Runtime &rt, jsi::String payload, jsi::String deviceID) = 0;
   virtual jsi::Value encryptAndPersist(jsi::Runtime &rt, jsi::String message, jsi::String deviceID, jsi::String messageID) = 0;
   virtual jsi::Value decrypt(jsi::Runtime &rt, jsi::Object encryptedData, jsi::String deviceID) = 0;
   virtual jsi::Value decryptSequentialAndPersist(jsi::Runtime &rt, jsi::Object encryptedData, jsi::String deviceID, jsi::String messageID) = 0;
@@ -305,6 +306,14 @@
       return bridging::callFromJs<jsi::Value>(
           rt, &T::encrypt, jsInvoker_, instance_, std::move(message), std::move(deviceID));
     }
+    jsi::Value encryptNotification(jsi::Runtime &rt, jsi::String payload, jsi::String deviceID) override {
+      static_assert(
+          bridging::getParameterCount(&T::encryptNotification) == 3,
+          "Expected encryptNotification(...) to have 3 parameters");
+
+      return bridging::callFromJs<jsi::Value>(
+          rt, &T::encryptNotification, jsInvoker_, instance_, std::move(payload), std::move(deviceID));
+    }
     jsi::Value encryptAndPersist(jsi::Runtime &rt, jsi::String message, jsi::String deviceID, jsi::String messageID) override {
       static_assert(
           bridging::getParameterCount(&T::encryptAndPersist) == 4,
diff --git a/native/push/encrypted-notif-utils-api.js b/native/push/encrypted-notif-utils-api.js
--- a/native/push/encrypted-notif-utils-api.js
+++ b/native/push/encrypted-notif-utils-api.js
@@ -2,7 +2,7 @@
 
 import type { EncryptedNotifUtilsAPI } from 'lib/types/notif-types.js';
 
-import { commUtilsModule } from '../native-modules.js';
+import { commUtilsModule, commCoreModule } from '../native-modules.js';
 
 const encryptedNotifUtilsAPI: EncryptedNotifUtilsAPI = {
   encryptSerializedNotifPayload: async (
@@ -13,16 +13,12 @@
       type: '1' | '0',
     ) => boolean,
   ) => {
-    // The "mock" implementation below will be replaced with proper
-    // implementation after olm notif sessions initialization is
-    // implemented. for now it is actually beneficial to return
-    // original string as encrypted string since it allows for
-    // better testing as we can verify which data are encrypted
-    // and which aren't.
+    const { message: body, messageType: type } =
+      await commCoreModule.encryptNotification(unencryptedPayload, cryptoID);
     return {
-      encryptedData: { body: unencryptedPayload, type: 1 },
+      encryptedData: { body, type },
       sizeLimitViolated: encryptedPayloadSizeValidator
-        ? !encryptedPayloadSizeValidator(unencryptedPayload, '1')
+        ? !encryptedPayloadSizeValidator(body, type ? '1' : '0')
         : false,
     };
   },
diff --git a/native/schema/CommCoreModuleSchema.js b/native/schema/CommCoreModuleSchema.js
--- a/native/schema/CommCoreModuleSchema.js
+++ b/native/schema/CommCoreModuleSchema.js
@@ -99,6 +99,10 @@
     deviceID: string,
   ) => Promise<EncryptedData>;
   +encrypt: (message: string, deviceID: string) => Promise<EncryptedData>;
+  +encryptNotification: (
+    payload: string,
+    deviceID: string,
+  ) => Promise<EncryptedData>;
   +encryptAndPersist: (
     message: string,
     deviceID: string,