diff --git a/matrix_sdk_crypto/src/device.rs b/matrix_sdk_crypto/src/device.rs
index 17804bca..bcd84fbd 100644
--- a/matrix_sdk_crypto/src/device.rs
+++ b/matrix_sdk_crypto/src/device.rs
@@ -36,6 +36,7 @@ pub struct Device {
     device_id: Arc<Box<DeviceId>>,
     algorithms: Arc<Vec<Algorithm>>,
     keys: Arc<BTreeMap<AlgorithmAndDeviceId, String>>,
+    signatures: Arc<BTreeMap<UserId, BTreeMap<AlgorithmAndDeviceId, String>>>,
     display_name: Arc<Option<String>>,
     deleted: Arc<AtomicBool>,
     trust_state: Arc<Atomic<TrustState>>,
@@ -75,12 +76,14 @@ impl Device {
         trust_state: TrustState,
         algorithms: Vec<Algorithm>,
         keys: BTreeMap<AlgorithmAndDeviceId, String>,
+        signatures: BTreeMap<UserId, BTreeMap<AlgorithmAndDeviceId, String>>,
     ) -> Self {
         Device {
             user_id: Arc::new(user_id),
             device_id: Arc::new(device_id),
             display_name: Arc::new(display_name),
             trust_state: Arc::new(Atomic::new(trust_state)),
+            signatures: Arc::new(signatures),
             algorithms: Arc::new(algorithms),
             keys: Arc::new(keys),
             deleted: Arc::new(AtomicBool::new(false)),
@@ -115,6 +118,11 @@ impl Device {
         &self.keys
     }
 
+    /// Get a map containing all the device signatures.
+    pub fn signatures(&self) -> &BTreeMap<UserId, BTreeMap<AlgorithmAndDeviceId, String>> {
+        &self.signatures
+    }
+
     /// Get the trust state of the device.
     pub fn trust_state(&self) -> TrustState {
         self.trust_state.load(Ordering::Relaxed)
@@ -144,6 +152,7 @@ impl Device {
 
         self.algorithms = Arc::new(device_keys.algorithms.clone());
         self.keys = Arc::new(device_keys.keys.clone());
+        self.signatures = Arc::new(device_keys.signatures.clone());
         self.display_name = display_name;
 
         Ok(())
@@ -180,6 +189,8 @@ impl Device {
 #[cfg(test)]
 impl From<&OlmMachine> for Device {
     fn from(machine: &OlmMachine) -> Self {
+        let signatures = BTreeMap::new();
+
         Device {
             user_id: Arc::new(machine.user_id().clone()),
             device_id: Arc::new(machine.device_id().into()),
@@ -204,6 +215,7 @@ impl From<&OlmMachine> for Device {
             ),
             display_name: Arc::new(None),
             deleted: Arc::new(AtomicBool::new(false)),
+            signatures: Arc::new(signatures),
             trust_state: Arc::new(Atomic::new(TrustState::Unset)),
         }
     }
@@ -217,6 +229,7 @@ impl TryFrom<&DeviceKeys> for Device {
             user_id: Arc::new(device_keys.user_id.clone()),
             device_id: Arc::new(device_keys.device_id.clone()),
             algorithms: Arc::new(device_keys.algorithms.clone()),
+            signatures: Arc::new(device_keys.signatures.clone()),
             keys: Arc::new(device_keys.keys.clone()),
             display_name: Arc::new(
                 device_keys
diff --git a/matrix_sdk_crypto/src/store/sqlite.rs b/matrix_sdk_crypto/src/store/sqlite.rs
index 76aec6ab..ba545a0c 100644
--- a/matrix_sdk_crypto/src/store/sqlite.rs
+++ b/matrix_sdk_crypto/src/store/sqlite.rs
@@ -272,6 +272,25 @@ impl SqliteStore {
             )
             .await?;
 
+        connection
+            .execute(
+                r#"
+            CREATE TABLE IF NOT EXISTS device_signatures (
+                "id" INTEGER NOT NULL PRIMARY KEY,
+                "device_id" INTEGER NOT NULL,
+                "user_id" TEXT NOT NULL,
+                "key_algorithm" TEXT NOT NULL,
+                "signature" TEXT NOT NULL,
+                FOREIGN KEY ("device_id") REFERENCES "devices" ("id")
+                    ON DELETE CASCADE
+                UNIQUE(device_id, user_id, key_algorithm)
+            );
+
+            CREATE INDEX IF NOT EXISTS "device_keys_device_id" ON "device_keys" ("device_id");
+        "#,
+            )
+            .await?;
+
         Ok(())
     }
 
@@ -473,19 +492,55 @@ impl SqliteStore {
                     .await?;
 
             let keys: BTreeMap<AlgorithmAndDeviceId, String> = key_rows
-                .iter()
+                .into_iter()
                 .filter_map(|row| {
-                    let algorithm: &str = &row.0;
-                    let algorithm = KeyAlgorithm::try_from(algorithm).ok()?;
-                    let key = &row.1;
+                    let algorithm = KeyAlgorithm::try_from(&*row.0).ok()?;
+                    let key = row.1;
 
                     Some((
                         AlgorithmAndDeviceId(algorithm, device_id.as_str().into()),
-                        key.to_owned(),
+                        key,
                     ))
                 })
                 .collect();
 
+            let signature_rows: Vec<(String, String, String)> = query_as(
+                "SELECT user_id, key_algorithm, signature
+                         FROM device_signatures WHERE device_id = ?",
+            )
+            .bind(device_row_id)
+            .fetch_all(&mut *connection)
+            .await?;
+
+            let mut signatures: BTreeMap<UserId, BTreeMap<AlgorithmAndDeviceId, String>> =
+                BTreeMap::new();
+
+            for row in signature_rows {
+                let user_id = if let Ok(u) = UserId::try_from(&*row.0) {
+                    u
+                } else {
+                    continue;
+                };
+
+                let key_algorithm = if let Ok(k) = KeyAlgorithm::try_from(&*row.1) {
+                    k
+                } else {
+                    continue;
+                };
+
+                let signature = row.2;
+
+                if !signatures.contains_key(&user_id) {
+                    let _ = signatures.insert(user_id.clone(), BTreeMap::new());
+                }
+                let user_map = signatures.get_mut(&user_id).unwrap();
+
+                user_map.insert(
+                    AlgorithmAndDeviceId(key_algorithm, device_id.as_str().into()),
+                    signature.to_owned(),
+                );
+            }
+
             let device = Device::new(
                 user_id,
                 device_id.as_str().into(),
@@ -493,6 +548,7 @@ impl SqliteStore {
                 trust_state,
                 algorithms,
                 keys,
+                signatures,
             );
 
             store.add(device);
@@ -562,6 +618,23 @@ impl SqliteStore {
             .await?;
         }
 
+        for (user_id, signature_map) in device.signatures() {
+            for (key_id, signature) in signature_map {
+                query(
+                    "INSERT OR IGNORE INTO device_signatures (
+                        device_id, user_id, key_algorithm, signature
+                     ) VALUES (?1, ?2, ?3, ?4)
+                     ",
+                )
+                .bind(device_row_id)
+                .bind(user_id.as_str())
+                .bind(key_id.0.to_string())
+                .bind(signature)
+                .execute(&mut *connection)
+                .await?;
+            }
+        }
+
         Ok(())
     }