# Configuring the message signature version on Amazon SNS topics
Configuring the message signature version

Configuring the message signature version on Amazon SNS topics allows you to enhance the security and compatibility of your message verification process.

Select between `SignatureVersion`**1** (SHA1) and `SignatureVersion`**2** (SHA256) to control the hashing algorithm used for signing messages. Amazon SNS topics default to `SignatureVersion`**1**. You can configure this setting using the [https://docs.amazonaws.cn/sns/latest/api/API_SetTopicAttributes.html](https://docs.amazonaws.cn/sns/latest/api/API_SetTopicAttributes.html) API action.

Use the following example to set the topic attribute `SignatureVersion` using the Amazon CLI:

```
aws sns set-topic-attributes \
    --topic-arn arn:aws-cn:sns:us-east-2:123456789012:MyTopic \
    --attribute-name SignatureVersion \
    --attribute-value 2
```