diff --git a/flake.lock b/flake.lock
index 5a9d972..45cbde5 100644
--- a/flake.lock
+++ b/flake.lock
@@ -84,11 +84,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1703657526,
-        "narHash": "sha256-C3fQG/tasnhtfJb0cvXthMDUJ/OLgCKNLqfMuR/M+0k=",
+        "lastModified": 1704498488,
+        "narHash": "sha256-yINKdShHrtjdiJhov+q0s3Y3B830ujRoSbHduUNyKag=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "d1d950841d230490f308f5fcf8c0d4f2bd3f24a7",
+        "rev": "51e44a13acea71b36245e8bd8c7db53e0a3e61ee",
         "type": "github"
       },
       "original": {
@@ -104,11 +104,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1703387252,
-        "narHash": "sha256-XKJqGj0BaEn/zyctEnkgVIh6Ba1rgTRc+UBi9EU8Y54=",
+        "lastModified": 1704596958,
+        "narHash": "sha256-BK3Ohsz7m8X6qVKFxDtr8KVcHipfr5hYE9PDIJevHbQ=",
         "owner": "Mic92",
         "repo": "nix-index-database",
-        "rev": "f4340c1a42c38d79293ba69bfd839fbd6268a538",
+        "rev": "f46800ac5a6e9f892fe36e50821c5d85794ecc62",
         "type": "github"
       },
       "original": {
@@ -128,11 +128,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1703639874,
-        "narHash": "sha256-54bkJbvGRb9Wq4re5tbtbHaFSPg7wnQfgAjCvggEDZ4=",
+        "lastModified": 1704590722,
+        "narHash": "sha256-exh2bDwYYkdJgm5wLvpWht5bRuPigk8v4Z7l4RegX3Q=",
         "owner": "nix-community",
         "repo": "nix-vscode-extensions",
-        "rev": "52061beda00305b26445dc84ca7ab8a6036685c4",
+        "rev": "7d0eace387cf4fd2812d0791684f4befa0865512",
         "type": "github"
       },
       "original": {
@@ -166,11 +166,11 @@
     },
     "nixos-hardware": {
       "locked": {
-        "lastModified": 1703545041,
-        "narHash": "sha256-nvQA+k1rSszrf4kA4eK2i/SGbzoXyoKHzzyzq/Jca1w=",
+        "lastModified": 1704632650,
+        "narHash": "sha256-83J/nd/NoLqo3vj0S0Ppqe8L+ijIFiGL6HNDfCCUD/Q=",
         "owner": "NixOS",
         "repo": "nixos-hardware",
-        "rev": "a15b6e525f5737a47b4ce28445c836996fb2ea8c",
+        "rev": "c478b3d56969006e015e55aaece4931f3600c1b2",
         "type": "github"
       },
       "original": {
@@ -182,11 +182,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1703438236,
-        "narHash": "sha256-aqVBq1u09yFhL7bj1/xyUeJjzr92fXVvQSSEx6AdB1M=",
+        "lastModified": 1704194953,
+        "narHash": "sha256-RtDKd8Mynhe5CFnVT8s0/0yqtWFMM9LmCzXv/YKxnq4=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "5f64a12a728902226210bf01d25ec6cbb9d9265b",
+        "rev": "bd645e8668ec6612439a9ee7e71f7eac4099d4f6",
         "type": "github"
       },
       "original": {
@@ -198,11 +198,11 @@
     },
     "nixpkgs-stable": {
       "locked": {
-        "lastModified": 1703351344,
-        "narHash": "sha256-9FEelzftkE9UaJ5nqxidaJJPEhe9TPhbypLHmc2Mysc=",
+        "lastModified": 1704290814,
+        "narHash": "sha256-LWvKHp7kGxk/GEtlrGYV68qIvPHkU9iToomNFGagixU=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "7790e078f8979a9fcd543f9a47427eeaba38f268",
+        "rev": "70bdadeb94ffc8806c0570eb5c2695ad29f0e421",
         "type": "github"
       },
       "original": {
@@ -214,11 +214,11 @@
     },
     "nixpkgs-stable_2": {
       "locked": {
-        "lastModified": 1703351344,
-        "narHash": "sha256-9FEelzftkE9UaJ5nqxidaJJPEhe9TPhbypLHmc2Mysc=",
+        "lastModified": 1704290814,
+        "narHash": "sha256-LWvKHp7kGxk/GEtlrGYV68qIvPHkU9iToomNFGagixU=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "7790e078f8979a9fcd543f9a47427eeaba38f268",
+        "rev": "70bdadeb94ffc8806c0570eb5c2695ad29f0e421",
         "type": "github"
       },
       "original": {
@@ -230,11 +230,11 @@
     },
     "nur": {
       "locked": {
-        "lastModified": 1703663873,
-        "narHash": "sha256-WHt475cqqOZp8+2FSZf3L6xVTQlIN8eAAVJzCeo8ydU=",
+        "lastModified": 1704645857,
+        "narHash": "sha256-YRFry+uleoeDKs0kr039eVCN5XSCOuUbgbyKMJRXeFY=",
         "owner": "nix-community",
         "repo": "NUR",
-        "rev": "e65636be64a336e7110fc82cf7aab577f1ed8233",
+        "rev": "e72bc8a4fff841c6a131fe40471e4ae401f31096",
         "type": "github"
       },
       "original": {
@@ -266,11 +266,11 @@
         "nixpkgs-stable": "nixpkgs-stable_2"
       },
       "locked": {
-        "lastModified": 1703387502,
-        "narHash": "sha256-JnWuQmyanPtF8c5yAEFXVWzaIlMxA3EAZCh8XNvnVqE=",
+        "lastModified": 1704596510,
+        "narHash": "sha256-tupdwwg1WeX2hNMOQrvtyafTaTVty0QC/gQp7yaYJic=",
         "owner": "Mic92",
         "repo": "sops-nix",
-        "rev": "e523e89763ff45f0a6cf15bcb1092636b1da9ed3",
+        "rev": "f5fbcc0f50e7fc60c4f806fa7a09abccf0826d8a",
         "type": "github"
       },
       "original": {
diff --git a/home/xin/calcite.nix b/home/xin/calcite.nix
index 31c9811..eecb258 100644
--- a/home/xin/calcite.nix
+++ b/home/xin/calcite.nix
@@ -36,7 +36,7 @@
     alacritty = { enable = true; };
     direnv = { enable = true; };
     fish = { enable = true; };
-    git = { enable = true; };
+    git = { enable = true; signing.enable = true; };
     neovim = { enable = true; };
     vscode = { enable = true; };
     zellij = { enable = true; };
diff --git a/modules/home-manager/git.nix b/modules/home-manager/git.nix
index 2b19136..e4b4c31 100644
--- a/modules/home-manager/git.nix
+++ b/modules/home-manager/git.nix
@@ -8,9 +8,20 @@ in
 {
   options.custom-hm.git = {
     enable = mkEnableOption "Enable git configuration";
+    signing = mkOption {
+      type = types.submodule {
+        options = {
+          enable = mkEnableOption "Git ssh signing";
+          keyFile = mkOption {
+            type = types.str;
+            default = "~/.ssh/id_ed25519_sk";
+          };
+        };
+      };
+    };
   };
   config = {
-    programs.git = {
+    programs.git = mkIf cfg.enable {
       enable = true;
       delta.enable = true;
       userName = "Xinyang Li";
@@ -21,6 +32,17 @@ in
         d = "diff";
         s = "status";
       };
+      signing = mkIf cfg.signing.enable { 
+        signByDefault = true;
+        key = cfg.signing.keyFile;
+      };
+      
+      extraConfig.user = mkIf cfg.signing.enable {
+        signingkey = cfg.signing.keyFile;
+      };
+      extraConfig.gpg = mkIf cfg.signing.enable {
+        format = "ssh";
+      };
     };
   };
-}
\ No newline at end of file
+}