diff --git a/matrix_sdk_crypto/src/store/memorystore.rs b/matrix_sdk_crypto/src/store/memorystore.rs
index 4cbe31db..2bccfb38 100644
--- a/matrix_sdk_crypto/src/store/memorystore.rs
+++ b/matrix_sdk_crypto/src/store/memorystore.rs
@@ -15,7 +15,7 @@
 use std::{collections::HashSet, sync::Arc};
 
 use async_trait::async_trait;
-use dashmap::DashSet;
+use dashmap::{DashMap, DashSet};
 use matrix_sdk_common::{
     identifiers::{DeviceId, RoomId, UserId},
     locks::Mutex,
@@ -34,6 +34,7 @@ pub struct MemoryStore {
     tracked_users: Arc<DashSet<UserId>>,
     users_for_key_query: Arc<DashSet<UserId>>,
     devices: DeviceStore,
+    identities: Arc<DashMap<UserId, UserIdentities>>,
 }
 
 impl MemoryStore {
@@ -44,6 +45,7 @@ impl MemoryStore {
             tracked_users: Arc::new(DashSet::new()),
             users_for_key_query: Arc::new(DashSet::new()),
             devices: DeviceStore::new(),
+            identities: Arc::new(DashMap::new()),
         }
     }
 }
@@ -133,8 +135,18 @@ impl CryptoStore for MemoryStore {
         Ok(())
     }
 
-    async fn get_user_identity(&self, _user_id: &UserId) -> Result<Option<UserIdentities>> {
-        Ok(None)
+    async fn get_user_identity(&self, user_id: &UserId) -> Result<Option<UserIdentities>> {
+        #[allow(clippy::map_clone)]
+        Ok(self.identities.get(user_id).map(|i| i.clone()))
+    }
+
+    async fn save_user_identities(&self, identities: &[UserIdentities]) -> Result<()> {
+        for identity in identities {
+            let _ = self
+                .identities
+                .insert(identity.user_id().to_owned(), identity.clone());
+        }
+        Ok(())
     }
 }
 
diff --git a/matrix_sdk_crypto/src/store/mod.rs b/matrix_sdk_crypto/src/store/mod.rs
index 6273a9ba..0bea21fc 100644
--- a/matrix_sdk_crypto/src/store/mod.rs
+++ b/matrix_sdk_crypto/src/store/mod.rs
@@ -199,6 +199,13 @@ pub trait CryptoStore: Debug {
     /// * `user_id` - The user for which we should get all the devices.
     async fn get_user_devices(&self, user_id: &UserId) -> Result<ReadOnlyUserDevices>;
 
+    /// Save the given user identities in the store.
+    ///
+    /// # Arguments
+    ///
+    /// * `identities` - The identities that should be saved in the store.
+    async fn save_user_identities(&self, identities: &[UserIdentities]) -> Result<()>;
+
     /// Get the user identity that is attached to the given user id.
     ///
     /// # Arguments
diff --git a/matrix_sdk_crypto/src/store/sqlite.rs b/matrix_sdk_crypto/src/store/sqlite.rs
index a44417aa..218c2ea2 100644
--- a/matrix_sdk_crypto/src/store/sqlite.rs
+++ b/matrix_sdk_crypto/src/store/sqlite.rs
@@ -888,6 +888,10 @@ impl CryptoStore for SqliteStore {
     async fn get_user_identity(&self, _user_id: &UserId) -> Result<Option<UserIdentities>> {
         Ok(None)
     }
+
+    async fn save_user_identities(&self, _users: &[UserIdentities]) -> Result<()> {
+        Ok(())
+    }
 }
 
 #[cfg(not(tarpaulin_include))]
diff --git a/matrix_sdk_crypto/src/user_identity.rs b/matrix_sdk_crypto/src/user_identity.rs
index 6141ea67..4c0f8197 100644
--- a/matrix_sdk_crypto/src/user_identity.rs
+++ b/matrix_sdk_crypto/src/user_identity.rs
@@ -153,6 +153,13 @@ pub enum UserIdentities {
 }
 
 impl UserIdentities {
+    pub fn user_id(&self) -> &UserId {
+        match self {
+            UserIdentities::Own(i) => i.user_id(),
+            UserIdentities::Other(i) => i.user_id(),
+        }
+    }
+
     pub fn master_key(&self) -> &BTreeMap<String, String> {
         match self {
             UserIdentities::Own(i) => i.master_key(),
@@ -182,6 +189,10 @@ impl UserIdentity {
         })
     }
 
+    pub fn user_id(&self) -> &UserId {
+        &self.user_id
+    }
+
     pub fn master_key(&self) -> &BTreeMap<String, String> {
         &self.master_key.0.keys
     }
@@ -231,6 +242,10 @@ impl OwnUserIdentity {
         })
     }
 
+    pub fn user_id(&self) -> &UserId {
+        &self.user_id
+    }
+
     pub fn update(
         &mut self,
         master_key: MasterPubkey,