diff --git a/Cargo.lock b/Cargo.lock
index 99265ae..57aff74 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1768,7 +1768,6 @@ version = "0.1.0"
 name = "keyfork-frame"
 version = "0.1.0"
 dependencies = [
- "hex",
  "insta",
  "sha2",
  "thiserror",
@@ -1843,7 +1842,7 @@ dependencies = [
 name = "keyfork-slip10-test-data"
 version = "0.1.0"
 dependencies = [
- "hex",
+ "smex",
 ]
 
 [[package]]
diff --git a/crates/util/keyfork-frame/Cargo.toml b/crates/util/keyfork-frame/Cargo.toml
index fb0a2ed..4b9c5ca 100644
--- a/crates/util/keyfork-frame/Cargo.toml
+++ b/crates/util/keyfork-frame/Cargo.toml
@@ -16,7 +16,6 @@ sha2 = "0.10.7"
 
 # Personally audited
 thiserror = "1.0.47"
-hex = "0.4.3"
 
 # Optional, not personally audited
 tokio = { version = "1.32.0", optional = true, features = ["io-util"] }
diff --git a/crates/util/keyfork-frame/src/lib.rs b/crates/util/keyfork-frame/src/lib.rs
index 3d18bc6..649cb31 100644
--- a/crates/util/keyfork-frame/src/lib.rs
+++ b/crates/util/keyfork-frame/src/lib.rs
@@ -34,8 +34,8 @@ pub enum DecodeError {
     IncorrectLength(usize, u32),
 
     /// The provided checksum of the data did not match the locally-generated checksum.
-    #[error("Checksum did not match: Their {0} != Our {1}")]
-    BadChecksum(String, String),
+    #[error("Checksum did not match: Their {0:X?} != Our {1:X?}")]
+    BadChecksum(Vec<u8>, Vec<u8>),
 
     /// Data could not be read from the input source.
     #[error("Data could not be read from the input source: {0}")]
@@ -88,10 +88,7 @@ pub(crate) fn verify_checksum(data: &[u8]) -> Result<&[u8], DecodeError> {
     let content = &data[32..];
     let our_checksum = hash(content);
     if our_checksum != checksum {
-        return Err(DecodeError::BadChecksum(
-            hex::encode(checksum),
-            hex::encode(our_checksum),
-        ));
+        return Err(DecodeError::BadChecksum(checksum.to_vec(), our_checksum));
     }
     Ok(content)
 }
diff --git a/crates/util/keyfork-slip10-test-data/Cargo.toml b/crates/util/keyfork-slip10-test-data/Cargo.toml
index 9719736..153f04a 100644
--- a/crates/util/keyfork-slip10-test-data/Cargo.toml
+++ b/crates/util/keyfork-slip10-test-data/Cargo.toml
@@ -4,7 +4,5 @@ version = "0.1.0"
 edition = "2021"
 license = "MIT"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
-hex = "0.4.3"
+smex = { version = "0.1.0", path = "../smex" }
diff --git a/crates/util/keyfork-slip10-test-data/src/lib.rs b/crates/util/keyfork-slip10-test-data/src/lib.rs
index 1384cc3..3d5047e 100644
--- a/crates/util/keyfork-slip10-test-data/src/lib.rs
+++ b/crates/util/keyfork-slip10-test-data/src/lib.rs
@@ -31,166 +31,166 @@ pub fn test_data() -> Result<HashMap<String, Vec<TestData>>, Box<dyn std::error:
     let mut map = HashMap::new();
     let secp256k1 = vec![
         TestData {
-            seed: hex::decode("000102030405060708090a0b0c0d0e0f")?,
+            seed: smex::decode("000102030405060708090a0b0c0d0e0f")?,
             tests: vec![
                 Test {
                     chain: "m",
-                    fingerprint: hex::decode("00000000")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("00000000")?,
+                    chain_code: smex::decode(
                         "873dff81c02f525623fd1fe5167eac3a55a049de3d314bb42ee227ffed37d508",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "e8f32e723decf4051aefac8e2c93c9c5b214313817cdb01a1494b917c8436b35",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "0339a36013301597daef41fbe593a02cc513d0b55527ec2df1050e2e8ff49c85c2",
                     )?,
                 },
                 Test {
                     chain: "m/0'",
-                    fingerprint: hex::decode("3442193e")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("3442193e")?,
+                    chain_code: smex::decode(
                         "47fdacbd0f1097043b78c63c20c34ef4ed9a111d980047ad16282c7ae6236141",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "edb2e14f9ee77d26dd93b4ecede8d16ed408ce149b6cd80b0715a2d911a0afea",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "035a784662a4a20a65bf6aab9ae98a6c068a81c52e4b032c0fb5400c706cfccc56",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1",
-                    fingerprint: hex::decode("5c1bd648")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("5c1bd648")?,
+                    chain_code: smex::decode(
                         "2a7857631386ba23dacac34180dd1983734e444fdbf774041578e9b6adb37c19",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "3c6cb8d0f6a264c91ea8b5030fadaa8e538b020f0a387421a12de9319dc93368",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "03501e454bf00751f24b1b489aa925215d66af2234e3891c3b21a52bedb3cd711c",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1/2'",
-                    fingerprint: hex::decode("bef5a2f9")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("bef5a2f9")?,
+                    chain_code: smex::decode(
                         "04466b9cc8e161e966409ca52986c584f07e9dc81f735db683c3ff6ec7b1503f",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "cbce0d719ecf7431d88e6a89fa1483e02e35092af60c042b1df2ff59fa424dca",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "0357bfe1e341d01c69fe5654309956cbea516822fba8a601743a012a7896ee8dc2",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1/2'/2",
-                    fingerprint: hex::decode("ee7ab90c")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("ee7ab90c")?,
+                    chain_code: smex::decode(
                         "cfb71883f01676f587d023cc53a35bc7f88f724b1f8c2892ac1275ac822a3edd",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "0f479245fb19a38a1954c5c7c0ebab2f9bdfd96a17563ef28a6a4b1a2a764ef4",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "02e8445082a72f29b75ca48748a914df60622a609cacfce8ed0e35804560741d29",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1/2'/2/1000000000",
-                    fingerprint: hex::decode("d880d7d8")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("d880d7d8")?,
+                    chain_code: smex::decode(
                         "c783e67b921d2beb8f6b389cc646d7263b4145701dadd2161548a8b078e65e9e",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "471b76e389e528d6de6d816857e012c5455051cad6660850e58372a6c3e6e7c8",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "022a471424da5e657499d1ff51cb43c47481a03b1e77f951fe64cec9f5a48f7011",
                     )?,
                 },
             ],
         },
         TestData {
-            seed: hex::decode(SECP256K1_512)?,
+            seed: smex::decode(SECP256K1_512)?,
             tests: vec![
                 Test {
                     chain: "m",
-                    fingerprint: hex::decode("00000000")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("00000000")?,
+                    chain_code: smex::decode(
                         "60499f801b896d83179a4374aeb7822aaeaceaa0db1f85ee3e904c4defbd9689",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "4b03d6fc340455b363f51020ad3ecca4f0850280cf436c70c727923f6db46c3e",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "03cbcaa9c98c877a26977d00825c956a238e8dddfbd322cce4f74b0b5bd6ace4a7",
                     )?,
                 },
                 Test {
                     chain: "m/0",
-                    fingerprint: hex::decode("bd16bee5")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("bd16bee5")?,
+                    chain_code: smex::decode(
                         "f0909affaa7ee7abe5dd4e100598d4dc53cd709d5a5c2cac40e7412f232f7c9c",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "abe74a98f6c7eabee0428f53798f0ab8aa1bd37873999041703c742f15ac7e1e",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "02fc9e5af0ac8d9b3cecfe2a888e2117ba3d089d8585886c9c826b6b22a98d12ea",
                     )?,
                 },
                 Test {
                     chain: "m/0/2147483647'",
-                    fingerprint: hex::decode("5a61ff8e")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("5a61ff8e")?,
+                    chain_code: smex::decode(
                         "be17a268474a6bb9c61e1d720cf6215e2a88c5406c4aee7b38547f585c9a37d9",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "877c779ad9687164e9c2f4f0f4ff0340814392330693ce95a58fe18fd52e6e93",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "03c01e7425647bdefa82b12d9bad5e3e6865bee0502694b94ca58b666abc0a5c3b",
                     )?,
                 },
                 Test {
                     chain: "m/0/2147483647'/1",
-                    fingerprint: hex::decode("d8ab4937")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("d8ab4937")?,
+                    chain_code: smex::decode(
                         "f366f48f1ea9f2d1d3fe958c95ca84ea18e4c4ddb9366c336c927eb246fb38cb",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "704addf544a06e5ee4bea37098463c23613da32020d604506da8c0518e1da4b7",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "03a7d1d856deb74c508e05031f9895dab54626251b3806e16b4bd12e781a7df5b9",
                     )?,
                 },
                 Test {
                     chain: "m/0/2147483647'/1/2147483646'",
-                    fingerprint: hex::decode("78412e3a")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("78412e3a")?,
+                    chain_code: smex::decode(
                         "637807030d55d01f9a0cb3a7839515d796bd07706386a6eddf06cc29a65a0e29",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "f1c7c871a54a804afe328b4c83a1c33b8e5ff48f5087273f04efa83b247d6a2d",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "02d2b36900396c9282fa14628566582f206a5dd0bcc8d5e892611806cafb0301f0",
                     )?,
                 },
                 Test {
                     chain: "m/0/2147483647'/1/2147483646'/2",
-                    fingerprint: hex::decode("31a507b8")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("31a507b8")?,
+                    chain_code: smex::decode(
                         "9452b549be8cea3ecb7a84bec10dcfd94afe4d129ebfd3b3cb58eedf394ed271",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "bb7d39bdb83ecf58f2fd82b6d918341cbef428661ef01ab97c28a4842125ac23",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "024d902e1a2fc7a8755ab5b694c575fce742c48d9ff192e63df5193e4c7afe1f9c",
                     )?,
                 },
@@ -201,166 +201,166 @@ pub fn test_data() -> Result<HashMap<String, Vec<TestData>>, Box<dyn std::error:
 
     let ed25519 = vec![
         TestData {
-            seed: hex::decode("000102030405060708090a0b0c0d0e0f")?,
+            seed: smex::decode("000102030405060708090a0b0c0d0e0f")?,
             tests: vec![
                 Test {
                     chain: "m",
-                    fingerprint: hex::decode("00000000")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("00000000")?,
+                    chain_code: smex::decode(
                         "90046a93de5380a72b5e45010748567d5ea02bbf6522f979e05c0d8d8ca9fffb",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "2b4be7f19ee27bbf30c667b642d5f4aa69fd169872f8fc3059c08ebae2eb19e7",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "00a4b2856bfec510abab89753fac1ac0e1112364e7d250545963f135f2a33188ed",
                     )?,
                 },
                 Test {
                     chain: "m/0'",
-                    fingerprint: hex::decode("ddebc675")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("ddebc675")?,
+                    chain_code: smex::decode(
                         "8b59aa11380b624e81507a27fedda59fea6d0b779a778918a2fd3590e16e9c69",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "68e0fe46dfb67e368c75379acec591dad19df3cde26e63b93a8e704f1dade7a3",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "008c8a13df77a28f3445213a0f432fde644acaa215fc72dcdf300d5efaa85d350c",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1'",
-                    fingerprint: hex::decode("13dab143")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("13dab143")?,
+                    chain_code: smex::decode(
                         "a320425f77d1b5c2505a6b1b27382b37368ee640e3557c315416801243552f14",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "b1d0bad404bf35da785a64ca1ac54b2617211d2777696fbffaf208f746ae84f2",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "001932a5270f335bed617d5b935c80aedb1a35bd9fc1e31acafd5372c30f5c1187",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1'/2'",
-                    fingerprint: hex::decode("ebe4cb29")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("ebe4cb29")?,
+                    chain_code: smex::decode(
                         "2e69929e00b5ab250f49c3fb1c12f252de4fed2c1db88387094a0f8c4c9ccd6c",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "92a5b23c0b8a99e37d07df3fb9966917f5d06e02ddbd909c7e184371463e9fc9",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "00ae98736566d30ed0e9d2f4486a64bc95740d89c7db33f52121f8ea8f76ff0fc1",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1'/2'/2'",
-                    fingerprint: hex::decode("316ec1c6")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("316ec1c6")?,
+                    chain_code: smex::decode(
                         "8f6d87f93d750e0efccda017d662a1b31a266e4a6f5993b15f5c1f07f74dd5cc",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "30d1dc7e5fc04c31219ab25a27ae00b50f6fd66622f6e9c913253d6511d1e662",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "008abae2d66361c879b900d204ad2cc4984fa2aa344dd7ddc46007329ac76c429c",
                     )?,
                 },
                 Test {
                     chain: "m/0'/1'/2'/2'/1000000000'",
-                    fingerprint: hex::decode("d6322ccd")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("d6322ccd")?,
+                    chain_code: smex::decode(
                         "68789923a0cac2cd5a29172a475fe9e0fb14cd6adb5ad98a3fa70333e7afa230",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "8f94d394a8e8fd6b1bc2f3f49f5c47e385281d5c17e65324b0f62483e37e8793",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "003c24da049451555d51a7014a37337aa4e12d41e485abccfa46b47dfb2af54b7a",
                     )?,
                 },
             ],
         },
         TestData {
-            seed: hex::decode(ED25519_512)?,
+            seed: smex::decode(ED25519_512)?,
             tests: vec![
                 Test {
                     chain: "m",
-                    fingerprint: hex::decode("00000000")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("00000000")?,
+                    chain_code: smex::decode(
                         "ef70a74db9c3a5af931b5fe73ed8e1a53464133654fd55e7a66f8570b8e33c3b",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "171cb88b1b3c1db25add599712e36245d75bc65a1a5c9e18d76f9f2b1eab4012",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "008fe9693f8fa62a4305a140b9764c5ee01e455963744fe18204b4fb948249308a",
                     )?,
                 },
                 Test {
                     chain: "m/0'",
-                    fingerprint: hex::decode("31981b50")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("31981b50")?,
+                    chain_code: smex::decode(
                         "0b78a3226f915c082bf118f83618a618ab6dec793752624cbeb622acb562862d",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "1559eb2bbec5790b0c65d8693e4d0875b1747f4970ae8b650486ed7470845635",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "0086fab68dcb57aa196c77c5f264f215a112c22a912c10d123b0d03c3c28ef1037",
                     )?,
                 },
                 Test {
                     chain: "m/0'/2147483647'",
-                    fingerprint: hex::decode("1e9411b1")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("1e9411b1")?,
+                    chain_code: smex::decode(
                         "138f0b2551bcafeca6ff2aa88ba8ed0ed8de070841f0c4ef0165df8181eaad7f",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "ea4f5bfe8694d8bb74b7b59404632fd5968b774ed545e810de9c32a4fb4192f4",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "005ba3b9ac6e90e83effcd25ac4e58a1365a9e35a3d3ae5eb07b9e4d90bcf7506d",
                     )?,
                 },
                 Test {
                     chain: "m/0'/2147483647'/1'",
-                    fingerprint: hex::decode("fcadf38c")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("fcadf38c")?,
+                    chain_code: smex::decode(
                         "73bd9fff1cfbde33a1b846c27085f711c0fe2d66fd32e139d3ebc28e5a4a6b90",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "3757c7577170179c7868353ada796c839135b3d30554bbb74a4b1e4a5a58505c",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "002e66aa57069c86cc18249aecf5cb5a9cebbfd6fadeab056254763874a9352b45",
                     )?,
                 },
                 Test {
                     chain: "m/0'/2147483647'/1'/2147483646'",
-                    fingerprint: hex::decode("aca70953")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("aca70953")?,
+                    chain_code: smex::decode(
                         "0902fe8a29f9140480a00ef244bd183e8a13288e4412d8389d140aac1794825a",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "5837736c89570de861ebc173b1086da4f505d4adb387c6a1b1342d5e4ac9ec72",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "00e33c0f7d81d843c572275f287498e8d408654fdf0d1e065b84e2e6f157aab09b",
                     )?,
                 },
                 Test {
                     chain: "m/0'/2147483647'/1'/2147483646'/2'",
-                    fingerprint: hex::decode("422c654b")?,
-                    chain_code: hex::decode(
+                    fingerprint: smex::decode("422c654b")?,
+                    chain_code: smex::decode(
                         "5d70af781f3a37b829f0d060924d5e960bdc02e85423494afc0b1a41bbe196d4",
                     )?,
-                    private_key: hex::decode(
+                    private_key: smex::decode(
                         "551d333177df541ad876a60ea71f00447931c0a9da16f227c11ea080d7391b8d",
                     )?,
-                    public_key: hex::decode(
+                    public_key: smex::decode(
                         "0047150c75db263559a70d5778bf36abbab30fb061ad69f69ece61a72b0cfa4fc0",
                     )?,
                 },