diff --git a/mod.ts b/mod.ts
index c427db92e..ed666d8fd 100644
--- a/mod.ts
+++ b/mod.ts
@@ -24,6 +24,8 @@ export { DhkemP521HkdfSha512 } from "./src/kems/dhkemP521.ts";
 export { DhkemX25519HkdfSha256 } from "./src/kems/dhkemX25519.ts";
 export { DhkemX448HkdfSha512 } from "./src/kems/dhkemX448.ts";
 
-export { HkdfSha256, HkdfSha384, HkdfSha512 } from "./src/kdfs/hkdf.ts";
+export { HkdfSha256 } from "./src/kdfs/hkdfSha256.ts";
+export { HkdfSha384 } from "./src/kdfs/hkdfSha384.ts";
+export { HkdfSha512 } from "./src/kdfs/hkdfSha512.ts";
 export { Aes128Gcm, Aes256Gcm } from "./src/aeads/aesGcm.ts";
 export { Chacha20Poly1305 } from "./src/aeads/chacha20Poly1305.ts";
diff --git a/src/cipherSuite.ts b/src/cipherSuite.ts
index 84b72ea3d..b92f8bfe7 100644
--- a/src/cipherSuite.ts
+++ b/src/cipherSuite.ts
@@ -21,7 +21,9 @@ import { AeadId, KdfId, KemId, Mode } from "./identifiers.ts";
 import { Aes128Gcm, Aes256Gcm } from "./aeads/aesGcm.ts";
 import { ExportOnly } from "./aeads/exportOnly.ts";
 import { Chacha20Poly1305 } from "./aeads/chacha20Poly1305.ts";
-import { HkdfSha256, HkdfSha384, HkdfSha512 } from "./kdfs/hkdf.ts";
+import { HkdfSha256 } from "./kdfs/hkdfSha256.ts";
+import { HkdfSha384 } from "./kdfs/hkdfSha384.ts";
+import { HkdfSha512 } from "./kdfs/hkdfSha512.ts";
 import { RecipientContext } from "./recipientContext.ts";
 import { SenderContext } from "./senderContext.ts";
 import { loadSubtleCrypto } from "./webCrypto.ts";
diff --git a/src/kdfs/hkdf.ts b/src/kdfs/hkdf.ts
index 6e432c7ae..78c120d30 100644
--- a/src/kdfs/hkdf.ts
+++ b/src/kdfs/hkdf.ts
@@ -1,7 +1,3 @@
-import { hmac } from "npm:@noble/hashes@1.3.1/hmac";
-import { sha256 } from "npm:@noble/hashes@1.3.1/sha256";
-import { sha384, sha512 } from "npm:@noble/hashes@1.3.1/sha512";
-
 import type { KdfInterface } from "../interfaces/kdfInterface.ts";
 
 import { KdfId } from "../identifiers.ts";
@@ -9,7 +5,7 @@ import { KdfAlgorithm } from "../algorithm.ts";
 
 import * as consts from "../consts.ts";
 
-export class Hkdf extends KdfAlgorithm implements KdfInterface {
+export class HkdfNative extends KdfAlgorithm implements KdfInterface {
   public readonly id: KdfId = KdfId.HkdfSha256;
   public readonly hashSize: number = 0;
   protected readonly algHash: HmacKeyGenParams = {
@@ -58,29 +54,7 @@ export class Hkdf extends KdfAlgorithm implements KdfInterface {
       salt = new ArrayBuffer(this.hashSize);
     }
     if (salt.byteLength !== this.hashSize) {
-      // Web Cryptography API supports only Nh(hashSize) length key.
-      // In this case, fallback to the upper-layer hmac library.
-      switch (this.algHash.hash) {
-        case "SHA-256":
-          return hmac(
-            sha256,
-            new Uint8Array(salt),
-            new Uint8Array(ikm),
-          );
-        case "SHA-384":
-          return hmac(
-            sha384,
-            new Uint8Array(salt),
-            new Uint8Array(ikm),
-          );
-        default:
-          // case "SHA-512":
-          return hmac(
-            sha512,
-            new Uint8Array(salt),
-            new Uint8Array(ikm),
-          );
-      }
+      throw new Error("The salt length must be the same as the hashSize");
     }
     const key = await (this._api as SubtleCrypto).importKey(
       "raw",
@@ -188,7 +162,7 @@ export class Hkdf extends KdfAlgorithm implements KdfInterface {
   }
 }
 
-export class HkdfSha256 extends Hkdf implements KdfInterface {
+export class HkdfSha256Native extends HkdfNative {
   public readonly id: KdfId = KdfId.HkdfSha256;
   public readonly hashSize: number = 32;
   protected readonly algHash: HmacKeyGenParams = {
@@ -198,7 +172,7 @@ export class HkdfSha256 extends Hkdf implements KdfInterface {
   };
 }
 
-export class HkdfSha384 extends Hkdf implements KdfInterface {
+export class HkdfSha384Native extends HkdfNative {
   public readonly id: KdfId = KdfId.HkdfSha384;
   public readonly hashSize: number = 48;
   protected readonly algHash: HmacKeyGenParams = {
@@ -208,7 +182,7 @@ export class HkdfSha384 extends Hkdf implements KdfInterface {
   };
 }
 
-export class HkdfSha512 extends Hkdf implements KdfInterface {
+export class HkdfSha512Native extends HkdfNative {
   public readonly id: KdfId = KdfId.HkdfSha512;
   public readonly hashSize: number = 64;
   protected readonly algHash: HmacKeyGenParams = {
diff --git a/src/kdfs/hkdfSha256.ts b/src/kdfs/hkdfSha256.ts
new file mode 100644
index 000000000..d1e84c9aa
--- /dev/null
+++ b/src/kdfs/hkdfSha256.ts
@@ -0,0 +1,29 @@
+import { hmac } from "npm:@noble/hashes@1.3.1/hmac";
+import { sha256 } from "npm:@noble/hashes@1.3.1/sha256";
+
+import { HkdfSha256Native } from "./hkdf.ts";
+
+export class HkdfSha256 extends HkdfSha256Native {
+  public override async extract(
+    salt: ArrayBuffer,
+    ikm: ArrayBuffer,
+  ): Promise<ArrayBuffer> {
+    this.checkInit();
+    if (salt.byteLength === 0) {
+      salt = new ArrayBuffer(this.hashSize);
+    }
+    if (salt.byteLength !== this.hashSize) {
+      return hmac(sha256, new Uint8Array(salt), new Uint8Array(ikm));
+    }
+    const key = await (this._api as SubtleCrypto).importKey(
+      "raw",
+      salt,
+      this.algHash,
+      false,
+      [
+        "sign",
+      ],
+    );
+    return await (this._api as SubtleCrypto).sign("HMAC", key, ikm);
+  }
+}
diff --git a/src/kdfs/hkdfSha384.ts b/src/kdfs/hkdfSha384.ts
new file mode 100644
index 000000000..06573d5cf
--- /dev/null
+++ b/src/kdfs/hkdfSha384.ts
@@ -0,0 +1,29 @@
+import { hmac } from "npm:@noble/hashes@1.3.1/hmac";
+import { sha384 } from "npm:@noble/hashes@1.3.1/sha512";
+
+import { HkdfSha384Native } from "./hkdf.ts";
+
+export class HkdfSha384 extends HkdfSha384Native {
+  public override async extract(
+    salt: ArrayBuffer,
+    ikm: ArrayBuffer,
+  ): Promise<ArrayBuffer> {
+    this.checkInit();
+    if (salt.byteLength === 0) {
+      salt = new ArrayBuffer(this.hashSize);
+    }
+    if (salt.byteLength !== this.hashSize) {
+      return hmac(sha384, new Uint8Array(salt), new Uint8Array(ikm));
+    }
+    const key = await (this._api as SubtleCrypto).importKey(
+      "raw",
+      salt,
+      this.algHash,
+      false,
+      [
+        "sign",
+      ],
+    );
+    return await (this._api as SubtleCrypto).sign("HMAC", key, ikm);
+  }
+}
diff --git a/src/kdfs/hkdfSha512.ts b/src/kdfs/hkdfSha512.ts
new file mode 100644
index 000000000..e16547ac9
--- /dev/null
+++ b/src/kdfs/hkdfSha512.ts
@@ -0,0 +1,29 @@
+import { hmac } from "npm:@noble/hashes@1.3.1/hmac";
+import { sha512 } from "npm:@noble/hashes@1.3.1/sha512";
+
+import { HkdfSha512Native } from "./hkdf.ts";
+
+export class HkdfSha512 extends HkdfSha512Native {
+  public override async extract(
+    salt: ArrayBuffer,
+    ikm: ArrayBuffer,
+  ): Promise<ArrayBuffer> {
+    this.checkInit();
+    if (salt.byteLength === 0) {
+      salt = new ArrayBuffer(this.hashSize);
+    }
+    if (salt.byteLength !== this.hashSize) {
+      return hmac(sha512, new Uint8Array(salt), new Uint8Array(ikm));
+    }
+    const key = await (this._api as SubtleCrypto).importKey(
+      "raw",
+      salt,
+      this.algHash,
+      false,
+      [
+        "sign",
+      ],
+    );
+    return await (this._api as SubtleCrypto).sign("HMAC", key, ikm);
+  }
+}
diff --git a/src/kems/dhkemP256.ts b/src/kems/dhkemP256.ts
index 9ab3aa486..6b700d8b0 100644
--- a/src/kems/dhkemP256.ts
+++ b/src/kems/dhkemP256.ts
@@ -1,5 +1,5 @@
 import { KemId } from "../identifiers.ts";
-import { HkdfSha256 } from "../kdfs/hkdf.ts";
+import { HkdfSha256 } from "../kdfs/hkdfSha256.ts";
 import { Dhkem } from "./dhkem.ts";
 import { Ec } from "./dhkemPrimitives/ec.ts";
 
diff --git a/src/kems/dhkemP384.ts b/src/kems/dhkemP384.ts
index 39e595561..d7833c824 100644
--- a/src/kems/dhkemP384.ts
+++ b/src/kems/dhkemP384.ts
@@ -1,5 +1,5 @@
 import { KemId } from "../identifiers.ts";
-import { HkdfSha384 } from "../kdfs/hkdf.ts";
+import { HkdfSha384 } from "../kdfs/hkdfSha384.ts";
 import { Dhkem } from "./dhkem.ts";
 import { Ec } from "./dhkemPrimitives/ec.ts";
 
diff --git a/src/kems/dhkemP521.ts b/src/kems/dhkemP521.ts
index b4444a8c8..a5b338f96 100644
--- a/src/kems/dhkemP521.ts
+++ b/src/kems/dhkemP521.ts
@@ -1,5 +1,5 @@
 import { KemId } from "../identifiers.ts";
-import { HkdfSha512 } from "../kdfs/hkdf.ts";
+import { HkdfSha512 } from "../kdfs/hkdfSha512.ts";
 import { Dhkem } from "./dhkem.ts";
 import { Ec } from "./dhkemPrimitives/ec.ts";
 
diff --git a/src/kems/dhkemX25519.ts b/src/kems/dhkemX25519.ts
index 51ea8f6fd..dda39b26f 100644
--- a/src/kems/dhkemX25519.ts
+++ b/src/kems/dhkemX25519.ts
@@ -1,5 +1,5 @@
 import { KemId } from "../identifiers.ts";
-import { HkdfSha256 } from "../kdfs/hkdf.ts";
+import { HkdfSha256 } from "../kdfs/hkdfSha256.ts";
 import { Dhkem } from "./dhkem.ts";
 import { X25519 } from "./dhkemPrimitives/x25519.ts";
 
diff --git a/src/kems/dhkemX448.ts b/src/kems/dhkemX448.ts
index 86072a121..03fa7dcf3 100644
--- a/src/kems/dhkemX448.ts
+++ b/src/kems/dhkemX448.ts
@@ -1,5 +1,5 @@
 import { KemId } from "../identifiers.ts";
-import { HkdfSha512 } from "../kdfs/hkdf.ts";
+import { HkdfSha512 } from "../kdfs/hkdfSha512.ts";
 import { Dhkem } from "./dhkem.ts";
 import { X448 } from "./dhkemPrimitives/x448.ts";
 
diff --git a/test/cipherSuite.test.ts b/test/cipherSuite.test.ts
index 741f4780d..5b2ac0f3f 100644
--- a/test/cipherSuite.test.ts
+++ b/test/cipherSuite.test.ts
@@ -12,7 +12,9 @@ import { DhkemP384HkdfSha384 } from "../src/kems/dhkemP384.ts";
 import { DhkemP521HkdfSha512 } from "../src/kems/dhkemP521.ts";
 import { DhkemX25519HkdfSha256 } from "../src/kems/dhkemX25519.ts";
 import { DhkemX448HkdfSha512 } from "../src/kems/dhkemX448.ts";
-import { HkdfSha256, HkdfSha384, HkdfSha512 } from "../src/kdfs/hkdf.ts";
+import { HkdfSha256 } from "../src/kdfs/hkdfSha256.ts";
+import { HkdfSha384 } from "../src/kdfs/hkdfSha384.ts";
+import { HkdfSha512 } from "../src/kdfs/hkdfSha512.ts";
 import { Aes128Gcm } from "../src/aeads/aesGcm.ts";
 
 import * as errors from "../src/errors.ts";
diff --git a/test/encryptionContext.test.ts b/test/encryptionContext.test.ts
index fb0f08e4c..82953db8a 100644
--- a/test/encryptionContext.test.ts
+++ b/test/encryptionContext.test.ts
@@ -5,7 +5,7 @@ import { describe, it } from "testing/bdd.ts";
 import { CipherSuite } from "../src/cipherSuite.ts";
 import { EncryptionContext } from "../src/encryptionContext.ts";
 import { AeadId, KdfId, KemId } from "../src/identifiers.ts";
-import { HkdfSha256 } from "../src/kdfs/hkdf.ts";
+import { HkdfSha256 } from "../src/kdfs/hkdfSha256.ts";
 import { loadSubtleCrypto } from "../src/webCrypto.ts";
 import { i2Osp } from "../src/utils/misc.ts";
 import { ExportOnly } from "../src/aeads/exportOnly.ts";
diff --git a/test/kdfContext.test.ts b/test/kdfContext.test.ts
index bc68ecf5e..aef00adb0 100644
--- a/test/kdfContext.test.ts
+++ b/test/kdfContext.test.ts
@@ -2,7 +2,9 @@ import { assertEquals } from "testing/asserts.ts";
 
 import { describe, it } from "testing/bdd.ts";
 
-import { HkdfSha256, HkdfSha384, HkdfSha512 } from "../src/kdfs/hkdf.ts";
+import { HkdfSha256 } from "../src/kdfs/hkdfSha256.ts";
+import { HkdfSha384 } from "../src/kdfs/hkdfSha384.ts";
+import { HkdfSha512 } from "../src/kdfs/hkdfSha512.ts";
 import { AeadId, KdfId, KemId } from "../src/identifiers.ts";
 import { loadCrypto, loadSubtleCrypto } from "../src/webCrypto.ts";
 import { i2Osp } from "../src/utils/misc.ts";
diff --git a/x/dhkem-secp256k1/src/dhkem-secp256k1.ts b/x/dhkem-secp256k1/src/dhkem-secp256k1.ts
index 6863aa7a2..d18f15438 100644
--- a/x/dhkem-secp256k1/src/dhkem-secp256k1.ts
+++ b/x/dhkem-secp256k1/src/dhkem-secp256k1.ts
@@ -7,7 +7,7 @@ import type { KemInterface } from "../../../src/interfaces/kemInterface.ts";
 import { Algorithm } from "../../../src/algorithm.ts";
 import { KemId } from "../../../src/identifiers.ts";
 import { XCryptoKey } from "../../../src/xCryptoKey.ts";
-import { HkdfSha256 } from "../../../src/kdfs/hkdf.ts";
+import { HkdfSha256 } from "../../../src/kdfs/hkdfSha256.ts";
 import { Dhkem } from "../../../src/kems/dhkem.ts";
 
 import * as consts from "../../../src/consts.ts";