diff --git a/common/rpc-service.c b/common/rpc-service.c
index b86dbbe..b7633b0 100644
--- a/common/rpc-service.c
+++ b/common/rpc-service.c
@@ -15,6 +15,7 @@
 #include "seafile-error.h"
 #include "seafile-rpc.h"
 #include "mq-mgr.h"
+#include "password-hash.h"
 
 #ifdef SEAFILE_SERVER
 #include "web-accesstoken-mgr.h"
@@ -1131,6 +1132,181 @@ out:
     return ret;
 }
 
+static void
+set_pwd_hash_to_commit (SeafCommit *commit,
+                        SeafRepo *repo,
+                        const char *pwd_hash,
+                        const char *pwd_hash_algo,
+                        const char *pwd_hash_params)
+{
+    commit->repo_name = g_strdup (repo->name);
+    commit->repo_desc = g_strdup (repo->desc);
+    commit->encrypted = repo->encrypted;
+    commit->repaired = repo->repaired;
+    if (commit->encrypted) {
+        commit->enc_version = repo->enc_version;
+        if (commit->enc_version == 2) {
+            commit->random_key = g_strdup (repo->random_key);
+        } else if (commit->enc_version == 3) {
+            commit->random_key = g_strdup (repo->random_key);
+            commit->salt = g_strdup (repo->salt);
+        } else if (commit->enc_version == 4) {
+            commit->random_key = g_strdup (repo->random_key);
+            commit->salt = g_strdup (repo->salt);
+        }
+        commit->pwd_hash = g_strdup (pwd_hash);
+        commit->pwd_hash_algo = g_strdup (pwd_hash_algo);
+        commit->pwd_hash_params = g_strdup (pwd_hash_params);
+    }
+    commit->no_local_history = repo->no_local_history;
+    commit->version = repo->version;
+}
+
+int
+seafile_upgrade_repo_enc_algorithm (const char *repo_id,
+                                    const char *user,
+                                    const char *passwd,
+                                    const char *pwd_hash_algo,
+                                    const char *pwd_hash_params,
+                                    GError **error)
+{
+    SeafRepo *repo = NULL;
+    SeafCommit *commit = NULL, *parent = NULL;
+    int ret = 0;
+
+    if (!user) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS,
+                     "No user given");
+        return -1;
+    }
+
+    if (!passwd || passwd[0] == 0) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS,
+                     "Empty passwd");
+        return -1;
+    }
+
+    if (!is_uuid_valid (repo_id)) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "Invalid repo id");
+        return -1;
+    }
+
+    if (!pwd_hash_algo) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "Invalid pwd hash algorithm");
+        return -1;
+    }
+
+    if (g_strcmp0 (pwd_hash_algo, PWD_HASH_PDKDF2) != 0 &&
+        g_strcmp0 (pwd_hash_algo, PWD_HASH_ARGON2ID) != 0) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "Unsupported pwd hash algorithm");
+        return -1;
+    }
+
+    if (!pwd_hash_params) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "Invalid pwd hash params");
+        return -1;
+    }
+
+retry:
+    repo = seaf_repo_manager_get_repo (seaf->repo_mgr, repo_id);
+    if (!repo) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "No such library");
+        return -1;
+    }
+
+    if (g_strcmp0 (pwd_hash_algo, repo->pwd_hash_algo) == 0 &&
+        g_strcmp0 (pwd_hash_params, repo->pwd_hash_params) == 0) {
+        goto out;
+    }
+
+    if (!repo->encrypted) {
+        g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "Repo not encrypted");
+        ret = -1;
+        goto out;
+    }
+
+    if (repo->pwd_hash_algo) {
+        if (seafile_pwd_hash_verify_repo_passwd (repo->enc_version, repo_id, passwd, repo->salt,
+                                                 repo->pwd_hash, repo->pwd_hash_algo, repo->pwd_hash_params) < 0) {
+            g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "Incorrect password");
+            ret = 1;
+            goto out;
+        }
+    } else {
+        if (seafile_verify_repo_passwd (repo_id, passwd, repo->magic,
+                                        repo->enc_version, repo->salt) < 0) {
+            g_set_error (error, SEAFILE_DOMAIN, SEAF_ERR_BAD_ARGS, "Incorrect password");
+            ret = -1;
+            goto out;
+        }
+    }
+
+    parent = seaf_commit_manager_get_commit (seaf->commit_mgr,
+                                             repo->id, repo->version,
+                                             repo->head->commit_id);
+    if (!parent) {
+        seaf_warning ("Failed to get commit %s:%s.\n",
+                      repo->id, repo->head->commit_id);
+        ret = -1;
+        goto out;
+    }
+
+    char new_pwd_hash[65]= {0};
+
+    seafile_generate_pwd_hash (repo->enc_version, repo_id, passwd, repo->salt,
+                               pwd_hash_algo, pwd_hash_params, new_pwd_hash);
+
+    // To prevent clients that have already synced this repo from overwriting the modified encryption algorithm,
+    // delete all sync tokens.
+    if (seaf_delete_repo_tokens (repo) < 0) {
+        seaf_warning ("Failed to delete repo sync tokens, abort change pwd hash algorithm.\n");
+        ret = -1;
+        goto out;
+    }
+
+    memcpy (repo->pwd_hash, new_pwd_hash, 64);
+
+    commit = seaf_commit_new (NULL,
+                              repo->id,
+                              parent->root_id,
+                              user,
+                              EMPTY_SHA1,
+                              "Changed library password hash algorithm",
+                              0);
+    commit->parent_id = g_strdup(parent->commit_id);
+    set_pwd_hash_to_commit (commit, repo, new_pwd_hash, pwd_hash_algo, pwd_hash_params);
+
+    if (seaf_commit_manager_add_commit (seaf->commit_mgr, commit) < 0) {
+        ret = -1;
+        goto out;
+    }
+
+    seaf_branch_set_commit (repo->head, commit->commit_id);
+    if (seaf_branch_manager_test_and_update_branch (seaf->branch_mgr,
+                                                    repo->head,
+                                                    parent->commit_id,
+                                                    FALSE, NULL, NULL, NULL) < 0) {
+        seaf_repo_unref (repo);
+        seaf_commit_unref (commit);
+        seaf_commit_unref (parent);
+        repo = NULL;
+        commit = NULL;
+        parent = NULL;
+        goto retry;
+    }
+
+    if (seaf_passwd_manager_is_passwd_set (seaf->passwd_mgr, repo_id, user))
+        seaf_passwd_manager_set_passwd (seaf->passwd_mgr, repo_id,
+                                        user, passwd, error);
+
+out:
+    seaf_commit_unref (commit);
+    seaf_commit_unref (parent);
+    seaf_repo_unref (repo);
+
+    return ret;
+}
+
 int
 seafile_is_repo_owner (const char *email,
                        const char *repo_id,
diff --git a/common/seaf-utils.c b/common/seaf-utils.c
index 0a00b84..32ca1af 100644
--- a/common/seaf-utils.c
+++ b/common/seaf-utils.c
@@ -512,3 +512,75 @@ split_filename (const char *filename, char **name, char **ext)
         *ext = NULL;
     }
 }
+
+static gboolean
+collect_token_list (SeafDBRow *row, void *data)
+{
+    GList **p_tokens = data;
+    const char *token;
+
+    token = seaf_db_row_get_column_text (row, 0);
+    *p_tokens = g_list_prepend (*p_tokens, g_strdup(token));
+
+    return TRUE;
+}
+
+int
+seaf_delete_repo_tokens (SeafRepo *repo)
+{
+    int ret = 0;
+    const char *template;
+    GList *token_list = NULL;
+    GList *ptr;
+    GString *token_list_str = g_string_new ("");
+    GString *sql = g_string_new ("");
+    int rc;
+
+    template = "SELECT u.token FROM RepoUserToken as u WHERE u.repo_id=?";
+    rc = seaf_db_statement_foreach_row (seaf->db, template,
+                                        collect_token_list, &token_list,
+                                        1, "string", repo->id);
+    if (rc < 0) {
+        goto out;
+    }
+
+    if (rc == 0)
+        goto out;
+
+    for (ptr = token_list; ptr; ptr = ptr->next) {
+        const char *token = (char *)ptr->data;
+        seaf_message ("delete token: %s\n", token);
+        if (token_list_str->len == 0)
+            g_string_append_printf (token_list_str, "'%s'", token);
+        else
+            g_string_append_printf (token_list_str, ",'%s'", token);
+    }
+
+    /* Note that there is a size limit on sql query. In MySQL it's 1MB by default.
+     * Normally the token_list won't be that long.
+     */
+    g_string_printf (sql, "DELETE FROM RepoUserToken WHERE token in (%s)",
+                     token_list_str->str);
+    rc = seaf_db_statement_query (seaf->db, sql->str, 0);
+    if (rc < 0) {
+        goto out;
+    }
+
+    g_string_printf (sql, "DELETE FROM RepoTokenPeerInfo WHERE token in (%s)",
+                     token_list_str->str);
+    rc = seaf_db_statement_query (seaf->db, sql->str, 0);
+    if (rc < 0) {
+        goto out;
+    }
+
+out:
+    g_string_free (token_list_str, TRUE);
+    g_string_free (sql, TRUE);
+    g_list_free_full (token_list, (GDestroyNotify)g_free);
+
+    if (rc < 0) {
+        ret = -1;
+    }
+
+    return ret;
+}
diff --git a/common/seaf-utils.h b/common/seaf-utils.h
index 2401bed..46f62bc 100644
--- a/common/seaf-utils.h
+++ b/common/seaf-utils.h
@@ -28,4 +28,7 @@ seaf_parse_auth_token (const char *auth_token);
 void
 split_filename (const char *filename, char **name, char **ext);
 
+int
+seaf_delete_repo_tokens (SeafRepo *repo);
+
 #endif
diff --git a/include/seafile-rpc.h b/include/seafile-rpc.h
index 6d6bd4d..b987852 100644
--- a/include/seafile-rpc.h
+++ b/include/seafile-rpc.h
@@ -150,6 +150,14 @@ seafile_change_repo_passwd (const char *repo_id,
                             const char *user,
                             GError **error);
 
+int
+seafile_upgrade_repo_enc_algorithm (const char *repo_id,
+                                    const char *user,
+                                    const char *passwd,
+                                    const char *pwd_hash_algo,
+                                    const char *pwd_hash_params,
+                                    GError **error);
+
 /**
  * seafile_repo_size:
  * 
diff --git a/python/seafile/rpcclient.py b/python/seafile/rpcclient.py
index f73e40d..400a14d 100644
--- a/python/seafile/rpcclient.py
+++ b/python/seafile/rpcclient.py
@@ -640,6 +640,12 @@ class SeafServerThreadedRpcClient(NamedPipeClient):
         pass
     change_repo_passwd = seafile_change_repo_passwd
 
+    # Upgrade repo enc algorithm
+    @searpc_func("int", ["string", "string", "string", "string", "string"])
+    def seafile_upgrade_repo_enc_algorithm (repo_id, user, passwd, pwd_hash_algo, pwd_hash_params):
+        pass
+    upgrade_repo_enc_algorithm = seafile_upgrade_repo_enc_algorithm
+
     # Clean trash
     @searpc_func("int", ["string", "int"])
     def clean_up_repo_history(repo_id, keep_days):
diff --git a/python/seaserv/api.py b/python/seaserv/api.py
index 78309bb..381a780 100644
--- a/python/seaserv/api.py
+++ b/python/seaserv/api.py
@@ -72,6 +72,10 @@ class SeafileAPI(object):
     def change_repo_passwd(self, repo_id, old_passwd, new_passwd, user):
         return seafserv_threaded_rpc.change_repo_passwd(repo_id, old_passwd,
                                                         new_passwd, user)
+
+    def upgrade_repo_enc_algorithm (self, repo_id, user, passwd, pwd_hash_algo, pwd_hash_params):
+        return seafserv_threaded_rpc.upgrade_repo_enc_algorithm (repo_id, user, passwd,
+                                                                 pwd_hash_algo, pwd_hash_params)
     def check_passwd(self, repo_id, magic):
         return seafserv_threaded_rpc.check_passwd(repo_id, magic)
 
diff --git a/server/gc/fsck.c b/server/gc/fsck.c
index 1a1f298..ec2a793 100644
--- a/server/gc/fsck.c
+++ b/server/gc/fsck.c
@@ -281,77 +281,6 @@ out:
     return dir_id;
 }
 
-static gboolean
-collect_token_list (SeafDBRow *row, void *data)
-{
-    GList **p_tokens = data;
-    const char *token;
-
-    token = seaf_db_row_get_column_text (row, 0);
-    *p_tokens = g_list_prepend (*p_tokens, g_strdup(token));
-
-    return TRUE;
-}
-
-int
-delete_repo_tokens (SeafRepo *repo)
-{
-    int ret = 0;
-    const char *template;
-    GList *token_list = NULL;
-    GList *ptr;
-    GString *token_list_str = g_string_new ("");
-    GString *sql = g_string_new ("");
-    int rc;
-
-    template = "SELECT u.token FROM RepoUserToken as u WHERE u.repo_id=?";
-    rc = seaf_db_statement_foreach_row (seaf->db, template,
-                                        collect_token_list, &token_list,
-                                        1, "string", repo->id);
-    if (rc < 0) {
-        goto out;
-    }
-
-    if (rc == 0)
-        goto out;
-
-    for (ptr = token_list; ptr; ptr = ptr->next) {
-        const char *token = (char *)ptr->data;
-        if (token_list_str->len == 0)
-            g_string_append_printf (token_list_str, "'%s'", token);
-        else
-            g_string_append_printf (token_list_str, ",'%s'", token);
-    }
-
-    /* Note that there is a size limit on sql query. In MySQL it's 1MB by default.
-     * Normally the token_list won't be that long.
-     */
-    g_string_printf (sql, "DELETE FROM RepoUserToken WHERE token in (%s)",
-                     token_list_str->str);
-    rc = seaf_db_statement_query (seaf->db, sql->str, 0);
-    if (rc < 0) {
-        goto out;
-    }
-
-    g_string_printf (sql, "DELETE FROM RepoTokenPeerInfo WHERE token in (%s)",
-                     token_list_str->str);
-    rc = seaf_db_statement_query (seaf->db, sql->str, 0);
-    if (rc < 0) {
-        goto out;
-    }
-
-out:
-    g_string_free (token_list_str, TRUE);
-    g_string_free (sql, TRUE);
-    g_list_free_full (token_list, (GDestroyNotify)g_free);
-
-    if (rc < 0) {
-        ret = -1;
-    }
-
-    return ret;
-}
-
 static char *
 gen_repair_commit_desc (GList *repaired_files, GList *repaired_folders)
 {
@@ -385,7 +314,7 @@ static void
 reset_commit_to_repair (SeafRepo *repo, SeafCommit *parent, char *new_root_id,
                         GList *repaired_files, GList *repaired_folders)
 {
-    if (delete_repo_tokens (repo) < 0) {
+    if (seaf_delete_repo_tokens (repo) < 0) {
         seaf_warning ("Failed to delete repo sync tokens, abort repair.\n");
         return;
     }
diff --git a/server/seaf-server.c b/server/seaf-server.c
index eeabc04..8847834 100644
--- a/server/seaf-server.c
+++ b/server/seaf-server.c
@@ -120,6 +120,11 @@ static void start_rpc_service (const char *seafile_dir,
                                      "seafile_change_repo_passwd",
                                      searpc_signature_int__string_string_string_string());
 
+    searpc_server_register_function ("seafserv-threaded-rpcserver",
+                                     seafile_upgrade_repo_enc_algorithm,
+                                     "seafile_upgrade_repo_enc_algorithm",
+                                     searpc_signature_int__string_string_string_string_string());
+
     searpc_server_register_function ("seafserv-threaded-rpcserver",
                                      seafile_is_repo_owner,
                                      "seafile_is_repo_owner",
diff --git a/tests/test_password/test_password.py b/tests/test_password/test_password.py
index 966ed61..09d799f 100644
--- a/tests/test_password/test_password.py
+++ b/tests/test_password/test_password.py
@@ -79,3 +79,36 @@ def test_pwd_hash(rpc, enc_version, algo, params):
     assert api.is_password_set(repo.id, USER) == 0
 
     api.remove_repo(repo_id)
+
+@pytest.mark.parametrize('enc_version, algo, params',
+                         [(2, 'pbkdf2_sha256', '1000'), (3, 'pbkdf2_sha256', '1000'), ( 4, 'pbkdf2_sha256', '1000'),
+                         (2, 'argon2id', '2,102400,8'), (3, 'argon2id', '2,102400,8'), (4, 'argon2id', '2,102400,8')])
+def test_upgrade_pwd_hash(enc_version, algo, params):
+    test_repo_name = 'test_enc_repo'
+    test_repo_desc = 'test_enc_repo'
+    test_repo_passwd = 'test_enc_repo'
+    repo_id = api.create_repo(test_repo_name, test_repo_desc, USER,
+                              test_repo_passwd, enc_version)
+    assert repo_id
+
+    repo = api.get_repo(repo_id)
+    assert repo
+    assert repo.enc_version == enc_version
+    assert len(repo.random_key) == 96
+    if enc_version > 2:
+        assert len(repo.salt) == 64
+
+    api.upgrade_repo_enc_algorithm (repo.repo_id, USER, test_repo_passwd, algo, params) == 0
+
+    repo = api.get_repo(repo_id)
+    assert repo.pwd_hash_algo == algo;
+    assert repo.pwd_hash_params == params;
+    assert repo.pwd_hash
+
+    assert api.set_passwd(repo.id, USER, test_repo_passwd) == 0
+    assert api.get_decrypt_key(repo.id, USER)
+    assert api.is_password_set(repo.id, USER)
+    assert api.unset_passwd(repo.id, USER) == 0
+    assert api.is_password_set(repo.id, USER) == 0
+
+    api.remove_repo(repo_id)