> For the complete documentation index, see [llms.txt](https://ploegert.gitbook.io/til/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ploegert.gitbook.io/til/programmy/linux/is-app-installed/crypto/compute-hashes-with-pgcrypto.md).

# Compute Hashes With pgcrypto

The `pgcrypto` extension that comes with PostgreSQL adds access to some general hashing functions. Included are `md5`, `sha1`, `sha224`, `sha256`, `sha384` and `sha512`. Any of these hashing functions can be applied to an arbitrary string using the `digest` function. Here are example of the `md5` and `sha1` algorithms:

```sql
> create extension pgcrypto;
CREATE EXTENSION

> select digest('Hello, World!', 'md5');
               digest
------------------------------------
 \x65a8e27d8879283831b664bd8b7f0ad4

> select digest('Hello, World!', 'sha1');
                   digest
--------------------------------------------
 \x0a0a9f2a6772942557ab5355d76af442f8f65e01
```

See the [`pgcrypto` docs](http://www.postgresql.org/docs/current/static/pgcrypto.html) for more details.