diff --git a/app/src/main/java/io/legado/app/help/crypto/AsymmetricCrypto.kt b/app/src/main/java/io/legado/app/help/crypto/AsymmetricCrypto.kt
index fb2a2c302..de953e6cc 100644
--- a/app/src/main/java/io/legado/app/help/crypto/AsymmetricCrypto.kt
+++ b/app/src/main/java/io/legado/app/help/crypto/AsymmetricCrypto.kt
@@ -1,81 +1,86 @@
 package io.legado.app.help.crypto
 
-import cn.hutool.crypto.asymmetric.AsymmetricCrypto as HutoolAsymmetricCrypto
-import cn.hutool.crypto.asymmetric.KeyType
 import cn.hutool.crypto.KeyUtil
+import cn.hutool.crypto.asymmetric.KeyType
 import java.io.InputStream
+import cn.hutool.crypto.asymmetric.AsymmetricCrypto as HutoolAsymmetricCrypto
 
+@Suppress("unused")
 class AsymmetricCrypto(algorithm: String) : HutoolAsymmetricCrypto(algorithm) {
 
+    @Suppress("MemberVisibilityCanBePrivate")
     fun setPrivateKey(key: ByteArray): AsymmetricCrypto {
         setPrivateKey(
             KeyUtil.generatePrivateKey(this.algorithm, key)
         )
         return this
     }
+
     fun setPrivateKey(key: String): AsymmetricCrypto = setPrivateKey(key.encodeToByteArray())
 
+    @Suppress("MemberVisibilityCanBePrivate")
     fun setPublicKey(key: ByteArray): AsymmetricCrypto {
         setPublicKey(
             KeyUtil.generatePublicKey(this.algorithm, key)
         )
         return this
     }
+
     fun setPublicKey(key: String): AsymmetricCrypto = setPublicKey(key.encodeToByteArray())
 
     private fun getKeyType(usePublicKey: Boolean? = true): KeyType {
-        return when {
-            usePublicKey == true -> KeyType.PublicKey
+        return when (usePublicKey) {
+            true -> KeyType.PublicKey
             else -> KeyType.PrivateKey
         }
     }
 
     @JvmOverloads
     fun decrypt(data: Any, usePublicKey: Boolean? = true): ByteArray {
-        return when {
-            data is ByteArray -> decrypt(data, getKeyType(usePublicKey))
-            data is String -> decrypt(data, getKeyType(usePublicKey))
-            data is InputStream -> decrypt(data, getKeyType(usePublicKey))
+        return when (data) {
+            is ByteArray -> decrypt(data, getKeyType(usePublicKey))
+            is String -> decrypt(data, getKeyType(usePublicKey))
+            is InputStream -> decrypt(data, getKeyType(usePublicKey))
             else -> throw IllegalArgumentException("Unexpected input type")
         }
     }
 
     @JvmOverloads
     fun decryptStr(data: Any, usePublicKey: Boolean? = true): String {
-        return when {
-            data is ByteArray -> String(decrypt(data, getKeyType(usePublicKey)))
-            data is String -> decryptStr(data, getKeyType(usePublicKey))
-            data is InputStream -> String(decrypt(data, getKeyType(usePublicKey)))
+        return when (data) {
+            is ByteArray -> String(decrypt(data, getKeyType(usePublicKey)))
+            is String -> decryptStr(data, getKeyType(usePublicKey))
+            is InputStream -> String(decrypt(data, getKeyType(usePublicKey)))
             else -> throw IllegalArgumentException("Unexpected input type")
         }
     }
 
     @JvmOverloads
     fun encrypt(data: Any, usePublicKey: Boolean? = true): ByteArray {
-        return when {
-            data is ByteArray -> encrypt(data, getKeyType(usePublicKey))
-            data is String -> encrypt(data, getKeyType(usePublicKey))
-            data is InputStream -> encrypt(data, getKeyType(usePublicKey))
+        return when (data) {
+            is ByteArray -> encrypt(data, getKeyType(usePublicKey))
+            is String -> encrypt(data, getKeyType(usePublicKey))
+            is InputStream -> encrypt(data, getKeyType(usePublicKey))
             else -> throw IllegalArgumentException("Unexpected input type")
         }
     }
 
     @JvmOverloads
     fun encryptHex(data: Any, usePublicKey: Boolean? = true): String {
-        return when {
-            data is ByteArray -> encryptHex(data, getKeyType(usePublicKey))
-            data is String -> encryptHex(data, getKeyType(usePublicKey))
-            data is InputStream -> encryptHex(data, getKeyType(usePublicKey))
+        return when (data) {
+            is ByteArray -> encryptHex(data, getKeyType(usePublicKey))
+            is String -> encryptHex(data, getKeyType(usePublicKey))
+            is InputStream -> encryptHex(data, getKeyType(usePublicKey))
             else -> throw IllegalArgumentException("Unexpected input type")
         }
     }
 
     @JvmOverloads
     fun encryptBase64(data: Any, usePublicKey: Boolean? = true): String {
-        return when {
-            data is ByteArray -> encryptBase64(data, getKeyType(usePublicKey))
-            data is String -> encryptBase64(data, getKeyType(usePublicKey))
-            data is InputStream -> encryptBase64(data, getKeyType(usePublicKey))
+        return when (data) {
+            is ByteArray -> encryptBase64(data, getKeyType(usePublicKey))
+            is String -> encryptBase64(data, getKeyType(usePublicKey))
+            is InputStream -> encryptBase64(data, getKeyType(usePublicKey))
             else -> throw IllegalArgumentException("Unexpected input type")
         }
     }
diff --git a/app/src/main/java/io/legado/app/help/crypto/Sign.kt b/app/src/main/java/io/legado/app/help/crypto/Sign.kt
index 04a85669d..7f3031895 100644
--- a/app/src/main/java/io/legado/app/help/crypto/Sign.kt
+++ b/app/src/main/java/io/legado/app/help/crypto/Sign.kt
@@ -1,8 +1,9 @@
 package io.legado.app.help.crypto
 
-import cn.hutool.crypto.asymmetric.Sign as HutoolSign
 import cn.hutool.crypto.KeyUtil
+import cn.hutool.crypto.asymmetric.Sign as HutoolSign
 
+@Suppress("unused")
 class Sign(algorithm: String): HutoolSign(algorithm) {
 
     fun setPrivateKey(key: ByteArray): Sign {
@@ -11,6 +12,7 @@ class Sign(algorithm: String): HutoolSign(algorithm) {
         )
         return this
     }
+
     fun setPrivateKey(key: String): Sign = setPrivateKey(key.encodeToByteArray())
 
     fun setPublicKey(key: ByteArray): Sign {
@@ -19,6 +21,7 @@ class Sign(algorithm: String): HutoolSign(algorithm) {
         )
         return this
     }
+
     fun setPublicKey(key: String): Sign = setPublicKey(key.encodeToByteArray())
 
 }