diff --git a/ChangeLog b/ChangeLog
index 470b3379b5..bcfece2b6e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -46,6 +46,13 @@ Changes in version 0.2.0.5-alpha - 2007-??-??
       every time we change any piece of our config.
     - Fix a bug with AutomapHostsOnResolve that would always cause the second
       request to fail.  Bug reported by Kate.  Bugfix on 0.2.0.3-alpha.
+    - When loading bandwidth history, do not believe any information in
+      the future.  Fixes bug 434.
+    - When loading entry guard information, do not believe any information
+      in the future.
+    - When we have our clock set far in the future and generate an onion key,
+      then re-set our clock to be correct, we should not stop the onion
+      key from getting rotated.
 
 
 Changes in version 0.2.0.4-alpha - 2007-08-01
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index fd99c0f519..7dcbf71d29 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -2465,6 +2465,7 @@ entry_guards_parse_state(or_state_t *state, int set, char **msg)
   entry_guard_t *node = NULL;
   smartlist_t *new_entry_guards = smartlist_create();
   config_line_t *line;
+  time_t now = time(NULL);
 
   *msg = NULL;
   for (line = state->EntryGuards; line; line = line->next) {
@@ -2507,6 +2508,11 @@ entry_guards_parse_state(or_state_t *state, int set, char **msg)
                           "Bad time in EntryGuardDownSince/UnlistedSince");
         break;
       }
+      if (when > now) {
+        /* It's a bad idea to believe info in the future: you can wind
+         * up with timeouts that aren't allowed to happen for years. */
+        continue;
+      }
       if (strlen(line->value) >= ISO_TIME_LEN+ISO_TIME_LEN+1) {
         /* ignore failure */
         parse_iso_time(line->value+ISO_TIME_LEN+1, &last_try);
diff --git a/src/or/hibernate.c b/src/or/hibernate.c
index 621e042894..8e3c7332e7 100644
--- a/src/or/hibernate.c
+++ b/src/or/hibernate.c
@@ -696,6 +696,9 @@ read_bandwidth_usage(void)
     goto done;
   }
 
+  /* XXXX020 do something if the interval "starts" far in the future?
+   * or do we alrady handle that. */
+
   n_bytes_read_in_interval = n_read;
   n_bytes_written_in_interval = n_written;
   n_seconds_active_in_interval = n_seconds;
diff --git a/src/or/rephist.c b/src/or/rephist.c
index 1bb8775d8f..3228d24a3f 100644
--- a/src/or/rephist.c
+++ b/src/or/rephist.c
@@ -993,7 +993,8 @@ rep_hist_load_state(or_state_t *state, char **err)
     s_values =  r?state->BWHistoryReadValues:state->BWHistoryWriteValues;
     if (s_values && s_begins >= now - NUM_SECS_BW_SUM_INTERVAL*NUM_TOTALS) {
       start = s_begins - s_interval*(smartlist_len(s_values));
-
+      if (start > now)
+        continue;
       b->cur_obs_time = start;
       b->next_period = start + NUM_SECS_BW_SUM_INTERVAL;
       SMARTLIST_FOREACH(s_values, char *, cp, {
@@ -1002,8 +1003,10 @@ rep_hist_load_state(or_state_t *state, char **err)
           all_ok=0;
           log_notice(LD_GENERAL, "Could not parse '%s' into a number.'", cp);
         }
-        add_obs(b, start, v);
-        start += NUM_SECS_BW_SUM_INTERVAL;
+        if (start < now) {
+          add_obs(b, start, v);
+          start += NUM_SECS_BW_SUM_INTERVAL;
+        }
       });
     }
 
diff --git a/src/or/router.c b/src/or/router.c
index 135c115d1d..2c165a7aa8 100644
--- a/src/or/router.c
+++ b/src/or/router.c
@@ -332,6 +332,7 @@ init_keys(void)
   or_options_t *options = get_options();
   or_state_t *state = get_or_state();
   authority_type_t type;
+  time_t now = time(NULL);
 
   if (!key_lock)
     key_lock = tor_mutex_new();
@@ -389,14 +390,17 @@ init_keys(void)
   prkey = init_key_from_file(keydir, 1, LOG_ERR);
   if (!prkey) return -1;
   set_onion_key(prkey);
-  if (state->LastRotatedOnionKey > 100) { /* allow for some parsing slop. */
+  if (state->LastRotatedOnionKey > 100 && state->LastRotatedOnionKey < now) {
+    /* We allow for some parsing slop, but we don't want to risk accepting
+     * values in the distant future.  If we did, we might never rotate the
+     * onion key. */
     onionkey_set_at = state->LastRotatedOnionKey;
   } else {
     /* We have no LastRotatedOnionKey set; either we just created the key
      * or it's a holdover from 0.1.2.4-alpha-dev or earlier.  In either case,
      * start the clock ticking now so that we will eventually rotate it even
      * if we don't stay up for a full MIN_ONION_KEY_LIFETIME. */
-    state->LastRotatedOnionKey = onionkey_set_at = time(NULL);
+    state->LastRotatedOnionKey = onionkey_set_at = now;
     or_state_mark_dirty(state, options->AvoidDiskWrites ? time(NULL)+3600 : 0);
   }