diff --git a/crates/lox-library/src/bridge_table.rs b/crates/lox-library/src/bridge_table.rs
index 49a8a05..9e1b324 100644
--- a/crates/lox-library/src/bridge_table.rs
+++ b/crates/lox-library/src/bridge_table.rs
@@ -261,6 +261,9 @@ pub struct BridgeTable {
     // We maintain a list of keys that have been blocked, as well as the date of their blocking
     // so that they can be repurposed with new buckets eventually
     pub blocked_keys: Vec<(u32, u32)>,
+    // Similarly, we maintain a list of open entry buckets that will be listed as expired
+    // after 511 days
+    pub open_inv_keys: Vec<(u32, u32)>,
     /// The date the buckets were last encrypted to make the encbucket.
     /// The encbucket must be rebuilt each day so that the Bucket
     /// Reachability credentials in the buckets can be refreshed.
@@ -286,37 +289,76 @@ impl BridgeTable {
             .unwrap()
     }
 
-    // Since buckets are moved around in the bridge_table, finding a lookup key that
-    // does not overwrite existing bridges could become an issue. We keep a list
-    // of recycleable lookup keys from buckets that have been removed and prioritize
-    // this list before increasing the counter
-    fn find_next_available_key(&mut self) -> u32 {
+    // This function looks for and removes buckets so their indexes can be reused
+    // This should include buckets that have been blocked for a sufficiently long period
+    // that we no longer want to allow migration to the, or else, open-entry buckets that
+    // have been unblocked long enough to become trusted and who's users' credentials
+    // would have expired (after 511 days)
+
+    fn clean_up_expired_buckets(&mut self) {
+        // Consider including migration tables and check age of from buckets
+        // If an open-invitation bucket is more than 511 days old, it should be recycled
+        // If a blocked bridge is more than ?? 511 (the maximum validity of a credential in days)? days old, it should also be recycled
+
         // First check if there are any blocked indexes that are old enough to be replaced
         if !self.blocked_keys.is_empty()
-            && self.blocked_keys.iter().any(|&x| x.1 > self.today() + 30)
-        //Perhaps 30 should be changed to a later/earlier time
+            && self.blocked_keys.iter().any(|&x| x.1 > self.today() + 511)
+        //Perhaps 511 should be changed to an earlier time
         {
             let blocked_keys_clone = self.blocked_keys.clone();
             // If so, separate them from the fresh blockages
             let (expired, fresh): (Vec<(u32, u32)>, Vec<(u32, u32)>) = blocked_keys_clone
                 .into_iter()
-                .partition(|&x| x.1 > self.today() + 30);
+                .partition(|&x| x.1 > self.today() + 511);
             for item in expired {
                 let new_item = item.0;
+                // get the single bridge line and remove the open entry index from the reachable bridges
+                let bridge_line = self.buckets.get(&new_item).unwrap();
+                for item in self.reachable.get(bridge_line) {}
+                self.buckets.remove(&new_item);
+                self.keys.remove(&new_item);
                 //and add them to the recyclable keys
                 self.recycleable_keys.push(new_item);
             }
             // update the blocked_keys vector to only include the fresh keys
             self.blocked_keys = fresh
         }
+        // First check if there are any open invitation indexes that are old enough to be replaced
+        if !self.open_inv_keys.is_empty()
+            && self.open_inv_keys.iter().any(|&x| x.1 > self.today() + 511)
+        //Perhaps 511 should be changed to an earlier time
+        {
+            let open_inv_keys_clone = self.open_inv_keys.clone();
+            // If so, separate them from the fresh open invitation indexes
+            let (expired, fresh): (Vec<(u32, u32)>, Vec<(u32, u32)>) = open_inv_keys_clone
+                .into_iter()
+                .partition(|&x| x.1 > self.today() + 511);
+            for item in expired {
+                let new_item = item.0;
+                self.buckets.remove(&new_item);
+                self.keys.remove(&new_item);
+                //and add them to the recyclable keys
+                self.recycleable_keys.push(new_item);
+            }
+            // update the open_inv_keys vector to only include the fresh keys
+            self.open_inv_keys = fresh
+        }
+    }
+
+    // Since buckets are moved around in the bridge_table, finding a lookup key that
+    // does not overwrite existing bridges could become an issue. We keep a list
+    // of recycleable lookup keys from buckets that have been removed and prioritize
+    // this list before increasing the counter
+    fn find_next_available_key(&mut self) -> u32 {
+        self.clean_up_expired_buckets();
         if self.recycleable_keys.is_empty() {
             let mut test_index = 1;
             let mut test_counter = self.counter.wrapping_add(test_index);
-            while self.buckets.contains_key(&test_counter) {
-                for i in 0..5000 {
-                    test_index += i;
-                    test_counter = self.counter.wrapping_add(test_index);
-                }
+            let mut i = 0;
+            while self.buckets.contains_key(&test_counter) && i < 5000 {
+                test_index += i;
+                test_counter = self.counter.wrapping_add(test_index);
+                i += 1;
             }
             self.counter = self.counter.wrapping_add(test_index);
             self.counter
@@ -324,6 +366,7 @@ impl BridgeTable {
             self.recycleable_keys.pop().unwrap()
         }
     }
+
     /// Append a new bucket to the bridge table, returning its index
     pub fn new_bucket(&mut self, bucket: &[BridgeLine; MAX_BRIDGES_PER_BUCKET]) -> u32 {
         // Pick a random key to encrypt this bucket
diff --git a/crates/lox-library/src/lib.rs b/crates/lox-library/src/lib.rs
index 2e90b78..c5e6dc5 100644
--- a/crates/lox-library/src/lib.rs
+++ b/crates/lox-library/src/lib.rs
@@ -305,6 +305,7 @@ impl BridgeAuth {
         for b in bridges.iter() {
             single[0] = *b;
             let snum = self.bridge_table.new_bucket(&single);
+            self.bridge_table.open_inv_keys.push((snum, self.today()));
             bdb.insert_openinv(snum);
             self.trustup_migration_table.table.insert(snum, bnum);
         }
@@ -325,6 +326,9 @@ impl BridgeAuth {
         // How to check for bridges that aren't there/are extra?
         // After going through the update, make sure bridges in the table are the same and deal with discrepencies
         // This will be the bad/annoying part
+
+        //also use open_inv_keys and blocked_keys from bridge_table to remove expired keys from table.
+        // make sure this happens before they are removed from the structures in the bridge table
     }
 
     pub fn allocate_bridges(