diff --git a/src/main/resources/update/gitbucket-core_4.25.xml b/src/main/resources/update/gitbucket-core_4.25.xml
new file mode 100644
index 0000000..b02b11c
--- /dev/null
+++ b/src/main/resources/update/gitbucket-core_4.25.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<changeSet>
+  <modifyDataType columnName="PASSWORD" newDataType="varchar(200)" tableName="ACCOUNT"/>
+</changeSet>
diff --git a/src/main/scala/gitbucket/core/GitBucketCoreModule.scala b/src/main/scala/gitbucket/core/GitBucketCoreModule.scala
index 24885e4..33b19f4 100644
--- a/src/main/scala/gitbucket/core/GitBucketCoreModule.scala
+++ b/src/main/scala/gitbucket/core/GitBucketCoreModule.scala
@@ -53,5 +53,6 @@
       new Version("4.23.0", new LiquibaseMigration("update/gitbucket-core_4.23.xml")),
       new Version("4.23.1"),
       new Version("4.24.0", new LiquibaseMigration("update/gitbucket-core_4.24.xml")),
-      new Version("4.24.1")
+      new Version("4.24.1"),
+      new Version("4.25.0", new LiquibaseMigration("update/gitbucket-core_4.25.xml"))
     )
diff --git a/src/main/scala/gitbucket/core/controller/AccountController.scala b/src/main/scala/gitbucket/core/controller/AccountController.scala
index 99a0bac..a8fc4ce 100644
--- a/src/main/scala/gitbucket/core/controller/AccountController.scala
+++ b/src/main/scala/gitbucket/core/controller/AccountController.scala
@@ -322,7 +322,7 @@
       account =>
         updateAccount(
           account.copy(
-            password = form.password.map(sha1).getOrElse(account.password),
+            password = form.password.map(pbkdf2_sha256).getOrElse(account.password),
             fullName = form.fullName,
             mailAddress = form.mailAddress,
             description = form.description,
@@ -563,7 +563,7 @@
     if (context.settings.allowAccountRegistration) {
       createAccount(
         form.userName,
-        sha1(form.password),
+        pbkdf2_sha256(form.password),
         form.fullName,
         form.mailAddress,
         false,
diff --git a/src/main/scala/gitbucket/core/controller/SystemSettingsController.scala b/src/main/scala/gitbucket/core/controller/SystemSettingsController.scala
index fc82666..69f0223 100644
--- a/src/main/scala/gitbucket/core/controller/SystemSettingsController.scala
+++ b/src/main/scala/gitbucket/core/controller/SystemSettingsController.scala
@@ -417,7 +417,7 @@
   post("/admin/users/_newuser", newUserForm)(adminOnly { form =>
     createAccount(
       form.userName,
-      sha1(form.password),
+      pbkdf2_sha256(form.password),
       form.fullName,
       form.mailAddress,
       form.isAdmin,
@@ -457,7 +457,7 @@
 
           updateAccount(
             account.copy(
-              password = form.password.map(sha1).getOrElse(account.password),
+              password = form.password.map(pbkdf2_sha256).getOrElse(account.password),
               fullName = form.fullName,
               mailAddress = form.mailAddress,
               isAdmin = form.isAdmin,
diff --git a/src/main/scala/gitbucket/core/service/AccountService.scala b/src/main/scala/gitbucket/core/service/AccountService.scala
index 8f0ba63..ea851b1 100644
--- a/src/main/scala/gitbucket/core/service/AccountService.scala
+++ b/src/main/scala/gitbucket/core/service/AccountService.scala
@@ -33,7 +33,16 @@
    * Authenticate by internal database.
    */
   private def defaultAuthentication(userName: String, password: String)(implicit s: Session) = {
+    val pbkdf2re = """^\$pbkdf2-sha256\$(\d+)\$([0-9a-zA-Z+/=]+)\$([0-9a-zA-Z+/=]+)$""".r
     getAccountByUserName(userName).collect {
+      case account if !account.isGroupAccount =>
+        account.password match {
+          case pbkdf2re(iter, salt, hash) if (pbkdf2_sha256(iter.toInt, salt, password) == hash) => Some(account)
+          case p if p == sha1(password) =>
+            updateAccount(account.copy(password = pbkdf2_sha256(password)))
+            Some(account)
+          case _ => None
+        }
       case account if (!account.isGroupAccount && account.password == sha1(password)) => Some(account)
     } getOrElse None
   }
diff --git a/src/main/scala/gitbucket/core/util/StringUtil.scala b/src/main/scala/gitbucket/core/util/StringUtil.scala
index bbbe5b4..b470eeb 100644
--- a/src/main/scala/gitbucket/core/util/StringUtil.scala
+++ b/src/main/scala/gitbucket/core/util/StringUtil.scala
@@ -1,10 +1,13 @@
 package gitbucket.core.util
 
 import java.net.{URLDecoder, URLEncoder}
+import java.security.SecureRandom
 import java.util.{Base64, UUID}
 
 import org.mozilla.universalchardet.UniversalDetector
 import SyntaxSugars._
+import javax.crypto.SecretKeyFactory
+import javax.crypto.spec.PBEKeySpec
 import org.apache.commons.io.input.BOMInputStream
 import org.apache.commons.io.IOUtils
 
@@ -16,6 +19,32 @@
     UUID.randomUUID().toString.substring(0, 16)
   }
 
+  def base64Encode(value: Array[Byte]): String = {
+    Base64.getEncoder.encodeToString(value)
+  }
+
+  def base64Decode(value: String): Array[Byte] = {
+    Base64.getDecoder.decode(value)
+  }
+
+  def pbkdf2_sha256(iter: Int, salt: String, value: String): String = {
+    val keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256")
+    val ks = new PBEKeySpec(value.toCharArray, base64Decode(salt), iter, 256)
+    val s = keyFactory.generateSecret(ks)
+    base64Encode(s.getEncoded)
+  }
+
+  def pbkdf2_sha256(value: String) = {
+    val keyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256")
+    val secureRandom = new SecureRandom
+    val salt: Array[Byte] = new Array(32)
+    secureRandom.nextBytes(salt)
+    val iter = 100000
+    val ks = new PBEKeySpec(value.toCharArray, salt, iter, 256)
+    val s = keyFactory.generateSecret(ks)
+    s"""$$pbkdf2-sha256$$${iter}$$${base64Encode(salt)}$$${base64Encode(s.getEncoded)}"""
+  }
+
   def sha1(value: String): String =
     defining(java.security.MessageDigest.getInstance("SHA-1")) { md =>
       md.update(value.getBytes)