diff --git a/.vscode/settings.json b/.vscode/settings.json
index 4e05f85..f5a7cba 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -5,16 +5,19 @@
     "Authorise",
     "Inequal",
     "KRISTWALLET",
+    "KRISTWALLETEXTENSION",
     "Lngs",
     "Sider",
     "Syncable",
     "Transpiler",
     "antd",
     "anticon",
+    "appendhashes",
     "arraybuffer",
     "authorised",
     "clientside",
     "dont",
+    "jwalelset",
     "languagedetector",
     "localisation",
     "multiline",
diff --git a/public/locales/en/translation.json b/public/locales/en/translation.json
index b4fc496..0022610 100644
--- a/public/locales/en/translation.json
+++ b/public/locales/en/translation.json
@@ -132,6 +132,8 @@
     "walletCategoryDropdownNewPlaceholder": "Category name",
 
     "walletAddress": "Wallet address",
+    "walletUsername": "Wallet username",
+    "walletUsernamePlaceholder": "Wallet username",
     "walletPassword": "Wallet password",
     "walletPasswordPlaceholder": "Wallet password",
     "walletPasswordWarning": "Make sure to save this somewhere <1>secure</1>!",
@@ -143,6 +145,8 @@
 
     "walletFormat": "Wallet format",
     "walletFormatKristWallet": "KristWallet, KWallet (recommended)",
+    "walletFormatKristWalletUsernameAppendhashes": "KW-Username (appendhashes)",
+    "walletFormatKristWalletUsername": "KW-Username (pre-appendhashes)",
     "walletFormatApi": "Raw/API (advanced users)",
 
     "walletSave": "Save this wallet in KristWeb"
diff --git a/src/krist/wallets/formats/WalletFormat.ts b/src/krist/wallets/formats/WalletFormat.ts
index 0622b3c..d9c2389 100644
--- a/src/krist/wallets/formats/WalletFormat.ts
+++ b/src/krist/wallets/formats/WalletFormat.ts
@@ -4,18 +4,26 @@
   (password: string, username?: string): Promise<string>;
 }
 
-export const KristWalletFormat: WalletFormat
-  = async password => await sha256("KRISTWALLET" + password) + "-000";
+export type WalletFormatName = "kristwallet" | "kristwallet_username_appendhashes" | "kristwallet_username" | "jwalelset" | "api";
+export const WALLET_FORMATS: Record<WalletFormatName, WalletFormat> = {
+  "kristwallet": async password =>
+    await sha256("KRISTWALLET" + password) + "-000",
 
-export const APIFormat: WalletFormat
-  = async password => password;
+  "kristwallet_username_appendhashes": async (password, username) =>
+    await sha256("KRISTWALLETEXTENSION" + await sha256(await sha256(username || "") + "^" + await sha256(password))) + "-000",
 
-export type WalletFormatName = "kristwallet" | "api";
-export const WalletFormatMap: Record<WalletFormatName, WalletFormat> = {
-  "kristwallet": KristWalletFormat,
-  "api": APIFormat
+  "kristwallet_username": async (password, username) =>
+    await sha256(await sha256(username || "") + "^" + await sha256(password)),
+
+  "jwalelset": async password =>
+    await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(await sha256(password)))))))))))))))))),
+
+  "api": async password => password
 };
 
 export const applyWalletFormat =
-  (format: WalletFormatName, password: string): Promise<string> =>
-    WalletFormatMap[format](password);
+  (format: WalletFormatName, password: string, username?: string): Promise<string> =>
+    WALLET_FORMATS[format](password, username);
+
+export const formatNeedsUsername = (format: WalletFormatName): boolean =>
+  WALLET_FORMATS[format].length === 2;
diff --git a/src/pages/wallets/AddWalletModal.tsx b/src/pages/wallets/AddWalletModal.tsx
index 581856c..cf1f20b 100644
--- a/src/pages/wallets/AddWalletModal.tsx
+++ b/src/pages/wallets/AddWalletModal.tsx
@@ -9,7 +9,7 @@
 import { FakeUsernameInput } from "../../components/auth/FakeUsernameInput";
 import { CopyInputButton } from "../../components/CopyInputButton";
 import { getWalletCategoryDropdown } from "../../components/wallets/WalletCategoryDropdown";
-import { WalletFormatName, applyWalletFormat } from "../../krist/wallets/formats/WalletFormat";
+import { WalletFormatName, applyWalletFormat, formatNeedsUsername } from "../../krist/wallets/formats/WalletFormat";
 import { makeV2Address } from "../../krist/AddressAlgo";
 
 const { Text } = Typography;
@@ -18,6 +18,7 @@
   label?: string;
   category: string;
 
+  walletUsername: string;
   password: string;
   format: WalletFormatName;
 
@@ -49,13 +50,13 @@
   function onValuesChange(changed: Partial<FormValues>, values: Partial<FormValues>) {
     if (changed.format) setFormatState(changed.format);
 
-    if ((changed.format || changed.password) && values.password)
-      updateCalculatedAddress(values.format, values.password);
+    if ((changed.format || changed.password || changed.walletUsername) && values.password)
+      updateCalculatedAddress(values.format, values.password, values.walletUsername);
   }
 
   /** Update the 'Wallet address' field */
-  async function updateCalculatedAddress(format: WalletFormatName | undefined, password: string) {
-    const privatekey = await applyWalletFormat(format || "kristwallet", password);
+  async function updateCalculatedAddress(format: WalletFormatName | undefined, password: string, username?: string) {
+    const privatekey = await applyWalletFormat(format || "kristwallet", password, username);
     const address = await makeV2Address(privatekey);
     setCalculatedAddress(address);
   }
@@ -120,10 +121,16 @@
         </Col>
       </Row>
 
-
       {/* Fake username input to trick browser autofill */}
       <FakeUsernameInput />
 
+      {/* Wallet username, if applicable */}
+      {formatState && formatNeedsUsername(formatState) && (
+        <Form.Item name="walletUsername" label={t("addWallet.walletUsername")}>
+          <Input type="text" autoComplete="off" placeholder={t("addWallet.walletUsernamePlaceholder")}/>
+        </Form.Item>
+      )}
+
       {/* Wallet password */}
       <Form.Item
         label={formatState === "api"
@@ -174,6 +181,8 @@
           <Form.Item name="format" label={t("addWallet.walletFormat")}>
             <Select>
               <Select.Option value="kristwallet">{t("addWallet.walletFormatKristWallet")}</Select.Option>
+              <Select.Option value="kristwallet_username_appendhashes">{t("addWallet.walletFormatKristWalletUsernameAppendhashes")}</Select.Option>
+              <Select.Option value="kristwallet_username">{t("addWallet.walletFormatKristWalletUsername")}</Select.Option>
               <Select.Option value="api">{t("addWallet.walletFormatApi")}</Select.Option>
             </Select>
           </Form.Item>