diff --git a/keyserver/flow-typed/npm/@commapp/olm_vx.x.x.js b/keyserver/flow-typed/npm/@commapp/olm_vx.x.x.js
--- a/keyserver/flow-typed/npm/@commapp/olm_vx.x.x.js
+++ b/keyserver/flow-typed/npm/@commapp/olm_vx.x.x.js
@@ -32,7 +32,8 @@
     remove_one_time_keys(session: Session): void;
     generate_prekey(): void;
     prekey(): string;
-    unpublished_prekey(): string;
+    unpublished_prekey(): ?string;
+    prekey_signature(): ?string;
     forget_old_prekey(): void;
     mark_prekey_as_published(): void;
     last_prekey_publish_time(): number;
@@ -56,7 +57,9 @@
     create_outbound(
       account: Account,
       their_identity_key: string,
-      their_pre_key: string,
+      their_signing_key: string,
+      their_prekey: string,
+      their_prekey_signature: string,
       their_one_time_key: string,
     ): void;
     create_inbound(account: Account, one_time_key_message: string): void;
diff --git a/keyserver/package.json b/keyserver/package.json
--- a/keyserver/package.json
+++ b/keyserver/package.json
@@ -41,7 +41,7 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.13.10",
-    "@commapp/olm": "0.0.4",
+    "@commapp/olm": "0.0.7",
     "@parse/node-apn": "^3.2.0",
     "@vingle/bmp-js": "^0.2.5",
     "JSONStream": "^1.3.5",
diff --git a/native/cpp/CommonCpp/CryptoTools/CryptoModule.h b/native/cpp/CommonCpp/CryptoTools/CryptoModule.h
--- a/native/cpp/CommonCpp/CryptoTools/CryptoModule.h
+++ b/native/cpp/CommonCpp/CryptoTools/CryptoModule.h
@@ -49,6 +49,7 @@
       const std::string &targetUserId,
       const OlmBuffer &idKeys,
       const OlmBuffer &preKeys,
+      const OlmBuffer &preKeySignature,
       const OlmBuffer &oneTimeKeys,
       size_t keyIndex = 0);
   bool hasSessionFor(const std::string &targetUserId);
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
@@ -138,6 +138,7 @@
     const std::string &targetUserId,
     const OlmBuffer &idKeys,
     const OlmBuffer &preKeys,
+    const OlmBuffer &preKeySignature,
     const OlmBuffer &oneTimeKeys,
     size_t keyIndex) {
   if (this->hasSessionFor(targetUserId)) {
@@ -150,6 +151,7 @@
       this->keys.identityKeys.data(),
       idKeys,
       preKeys,
+      preKeySignature,
       oneTimeKeys,
       keyIndex);
   this->sessions.insert(make_pair(targetUserId, std::move(newSession)));
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
@@ -25,6 +25,7 @@
       std::uint8_t *ownerIdentityKeys,
       const OlmBuffer &idKeys,
       const OlmBuffer &preKeys,
+      const OlmBuffer &preKeySignature,
       const OlmBuffer &oneTimeKeys,
       size_t keyIndex = 0);
   static std::unique_ptr<Session> createSessionAsResponder(
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
@@ -11,6 +11,7 @@
     std::uint8_t *ownerIdentityKeys,
     const OlmBuffer &idKeys,
     const OlmBuffer &preKeys,
+    const OlmBuffer &preKeySignature,
     const OlmBuffer &oneTimeKeys,
     size_t keyIndex) {
   std::unique_ptr<Session> session(new Session(account, ownerIdentityKeys));
@@ -29,8 +30,12 @@
           session->ownerUserAccount,
           idKeys.data() + ID_KEYS_PREFIX_OFFSET,
           KEYSIZE,
+          idKeys.data() + SIGNING_KEYS_PREFIX_OFFSET,
+          KEYSIZE,
           preKeys.data() + PRE_KEY_PREFIX_OFFSET,
           KEYSIZE,
+          preKeySignature.data(),
+          SIGNATURESIZE,
           oneTimeKeys.data() + ONE_TIME_KEYS_PREFIX_OFFSET +
               (KEYSIZE + ONE_TIME_KEYS_MIDDLE_OFFSET) * keyIndex,
           KEYSIZE,
diff --git a/native/cpp/CommonCpp/CryptoTools/Tools.h b/native/cpp/CommonCpp/CryptoTools/Tools.h
--- a/native/cpp/CommonCpp/CryptoTools/Tools.h
+++ b/native/cpp/CommonCpp/CryptoTools/Tools.h
@@ -6,8 +6,12 @@
 
 #include "olm/olm.h"
 
+// base64-encoded
 #define KEYSIZE 43
+#define SIGNATURESIZE 86
+
 #define ID_KEYS_PREFIX_OFFSET 15
+#define SIGNING_KEYS_PREFIX_OFFSET 71
 #define PRE_KEY_PREFIX_OFFSET 25
 #define ONE_TIME_KEYS_PREFIX_OFFSET 25
 #define ONE_TIME_KEYS_MIDDLE_OFFSET 12
diff --git a/native/package.json b/native/package.json
--- a/native/package.json
+++ b/native/package.json
@@ -86,7 +86,7 @@
     "lodash": "^4.17.21",
     "lottie-react-native": "^5.1.4",
     "md5": "^2.2.1",
-    "olm": "git+https://github.com/CommE2E/olm.git#v0.0.4",
+    "olm": "git+https://github.com/CommE2E/olm.git#v0.0.7",
     "react": "18.1.0",
     "react-native": "^0.70.8",
     "react-native-background-upload": "^6.6.0",
diff --git a/web/flow-typed/npm/@commapp/olm_vx.x.x.js b/web/flow-typed/npm/@commapp/olm_vx.x.x.js
--- a/web/flow-typed/npm/@commapp/olm_vx.x.x.js
+++ b/web/flow-typed/npm/@commapp/olm_vx.x.x.js
@@ -32,7 +32,8 @@
     remove_one_time_keys(session: Session): void;
     generate_prekey(): void;
     prekey(): string;
-    unpublished_prekey(): string;
+    unpublished_prekey(): ?string;
+    prekey_signature(): ?string;
     forget_old_prekey(): void;
     mark_prekey_as_published(): void;
     last_prekey_publish_time(): number;
@@ -56,7 +57,9 @@
     create_outbound(
       account: Account,
       their_identity_key: string,
-      their_pre_key: string,
+      their_signing_key: string,
+      their_prekey: string,
+      their_prekey_signature: string,
       their_one_time_key: string,
     ): void;
     create_inbound(account: Account, one_time_key_message: string): void;
diff --git a/web/package.json b/web/package.json
--- a/web/package.json
+++ b/web/package.json
@@ -35,7 +35,7 @@
   },
   "dependencies": {
     "@babel/runtime": "^7.13.10",
-    "@commapp/olm": "0.0.4",
+    "@commapp/olm": "0.0.7",
     "@commapp/opaque-ke-wasm": "npm:@commapp/opaque-ke-wasm@^0.0.3",
     "@emoji-mart/data": "^1.1.2",
     "@emoji-mart/react": "^1.1.1",
diff --git a/yarn.lock b/yarn.lock
--- a/yarn.lock
+++ b/yarn.lock
@@ -1719,10 +1719,10 @@
     stream-browserify "^3.0.0"
     util "^0.12.4"
 
-"@commapp/olm@0.0.4":
-  version "0.0.4"
-  resolved "https://registry.yarnpkg.com/@commapp/olm/-/olm-0.0.4.tgz#cbab890fdc8767ea5336b052d6b0f9ea698ffd36"
-  integrity sha512-gEh2QAMRzH21EKncwL9jTUdVD+ZgBRmKW0Q+RGe0P1R12iJq5PW6xZJFgV+tQLnhgVZviKNlz1R8KphXhSy2ww==
+"@commapp/olm@0.0.6":
+  version "0.0.6"
+  resolved "https://registry.yarnpkg.com/@commapp/olm/-/olm-0.0.6.tgz#391d4f699d7f41a1cf711ac6765325cebf08e964"
+  integrity sha512-Y/590sZQmW/WS/hrdcJf4AKPff0/s2O/CdVg/4L00kU9KzoO0zSyD0anSRyYR/Q8Ym7Y2XpaLG8UFd+cf44NtA==
 
 "@commapp/opaque-ke-wasm@npm:@commapp/opaque-ke-wasm@^0.0.3":
   version "0.0.3"
@@ -17845,9 +17845,9 @@
   resolved "https://registry.yarnpkg.com/octokit-pagination-methods/-/octokit-pagination-methods-1.1.0.tgz#cf472edc9d551055f9ef73f6e42b4dbb4c80bea4"
   integrity sha512-fZ4qZdQ2nxJvtcasX7Ghl+WlWS/d9IgnBIwFZXVNNZUmzpno91SX5bc5vuxiuKoCtK78XxGGNuSCrDC7xYB3OQ==
 
-"olm@git+https://github.com/CommE2E/olm.git#v0.0.4":
+"olm@git+https://github.com/CommE2E/olm.git#v0.0.6":
   version "0.0.0"
-  resolved "git+https://github.com/CommE2E/olm.git#9ff2863a394399684e272c0665eb8629ef430714"
+  resolved "git+https://github.com/CommE2E/olm.git#59e96129d494ab6844cab93aa78cd9ede51d1547"
 
 on-finished@2.4.1:
   version "2.4.1"