site/source/docs/datafu/guide/hashing.html.markdown.erb

---
title: Hashing - Guide - Apache DataFu Pig
version: 1.4.0
section_name: Apache DataFu Pig - Guide
license: >
   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
---

## Hashing

### MD5

The [MD5 hash](http://en.wikipedia.org/wiki/MD5) of a string can be computed with the
[MD5](https://datafu.apache.org/docs/datafu/<%= current_page.data.version %>/datafu/pig/hash/MD5.html)
UDF.

For example:

```pig
define MD5 datafu.pig.hash.MD5();

--input: "hello, world!"
data_in = LOAD 'input' as (val:chararray);
data_out = FOREACH data_in GENERATE MD5(val) as val;

-- produces: (fc3ff98e8c6a0d3087d515c0473f8677)
DUMP data_out;
```

The function can instead output base64 by passing 'base64' to the constructor.
The default is 'hex' for hexadecimal.

```pig
define MD5 datafu.pig.hash.MD5('base64');
```

### SHA

A [SHA](http://en.wikipedia.org/wiki/Secure_Hash_Algorithm) hash can be computed with
[SHA](https://datafu.apache.org/docs/datafu/<%= current_page.data.version %>/datafu/pig/hash/SHA.html).
The output will be in hexadecimal.

```pig
define SHA datafu.pig.hash.SHA();

--input: "hello, world!"
data_in = LOAD 'input' as (val:chararray);
data_out = FOREACH data_in GENERATE SHA(val) as val;

-- produces: (7509e5bda0c762d2bac7f90d758b5b2263fa01ccbc542ab5e3df163be08e6ca9)
DUMP data_out;
```

By default this uses SHA-256.
The constructor also takes an optional parameter for the particular SHA algorithm to use.
To use SHA-512 instead:

```pig
define SHA512 datafu.pig.hash.SHA('512');
```