diff --git a/index.js b/index.js
index 03ccdc3..e9e30e2 100644
--- a/index.js
+++ b/index.js
@@ -31,22 +31,21 @@ my.COIN_LIST=['TIC','BTC','ETH']
 my.CHAINNET='mainnet' // 默认的链网
 
 module.exports = {
-  isHashable(data, option){
-    option=option||{}
-    if (option.strict) {
+  isHashable(data, {strict=false}={}){
+    if (strict) {
       return data && typeof(data)!=='boolean' && data!==Infinity // 允许大多数数据，除了空值、布尔值、无限数
     }
     return typeof(data)!=='undefined' // 允许一切数据，除非 undefined
   }
   ,
-  isHash(hash, option){
-    option=option||{}
-    option.hasher=my.HASHER_LIST.indexOf(option.hasher)>=0?option.hasher:my.HASHER
-    switch(option.hasher){
-      case 'sha256': return /^[a-fA-F0-9]{64}$/.test(hash)
-      case 'md5': return /^[a-fA-F0-9]{32}$/.test(hash)
-      case 'ripemd160': case 'sha1': return /^[a-fA-F0-9]{40}$/.test(hash)
-      case 'sha512': return /^[a-fA-F0-9]{128}$/.test(hash)
+  isHash(hash, {hasher=my.HASHER}={}){
+    if (my.HASHER_LIST.indexOf(hasher)>=0) {
+      switch(hasher){
+        case 'sha256': return /^[a-fA-F0-9]{64}$/.test(hash)
+        case 'md5': return /^[a-fA-F0-9]{32}$/.test(hash)
+        case 'ripemd160': case 'sha1': return /^[a-fA-F0-9]{40}$/.test(hash)
+        case 'sha512': return /^[a-fA-F0-9]{128}$/.test(hash)
+      }
     }
     return false
   }
@@ -87,16 +86,14 @@ module.exports = {
     return /^[a-fA-F0-9]{128,144}$/.test(signature) && (signature.length % 2 === 0) // 128 for nacl, 140/142/144 for crypto and eccrypto in der format.
   }
   ,
-  hash(data, option){ // data can be anything, but converts to string or remains be Buffer/TypedArray/DataView
+  hash(data, {hasher=my.HASHER, salt, input=my.INPUT, output=my.OUTPUT}={}){ // data can be anything, but converts to string or remains be Buffer/TypedArray/DataView
     if (this.isHashable(data)) {
-      option=option||{}
       if (typeof(data)!=='string' && !(data instanceof Buffer) && !(data instanceof DataView)) 
         data=JSON.stringify(data)
-      if (option.salt && typeof(option.salt)==='string')
-        data=data+this.hash(option.salt)
-      let hasher= my.HASHER_LIST.indexOf(option.hasher)>=0?option.hasher:my.HASHER // 默认为 sha256.      
-      let inputEncoding=my.INPUT_LIST.indexOf(option.input)>=0?option.input:my.INPUT // 'utf8', 'ascii' or 'latin1' for string data, default to utf8 if not specified; ignored for Buffer, TypedArray, or DataView.
-      let outputEncoding=(option.output==='buf')?undefined:(my.OUTPUT_LIST.indexOf(option.output)>=0?option.output:my.OUTPUT)  // option.output: 留空=》默认输出hex格式；或者手动指定 'buf', hex', 'latin1' or 'base64'
+      if (salt && typeof(salt)==='string')
+        data=data+this.hash(salt)
+      let inputEncoding=input // my.INPUT_LIST.indexOf(option.input)>=0?option.input:my.INPUT // 'utf8', 'ascii' or 'latin1' for string data, default to utf8 if not specified; ignored for Buffer, TypedArray, or DataView.
+      let outputEncoding=(output==='buf')?undefined:output // (my.OUTPUT_LIST.indexOf(output)>=0?output:my.OUTPUT)  // option.output: 留空=》默认输出hex格式；或者手动指定 'buf', hex', 'latin1' or 'base64'
       return crypto.createHash(hasher).update(data, inputEncoding).digest(outputEncoding)
     }
     return null