---
title: Hash a byte payload
summary: Compute an MD5 hash of a byte payload.
status: draft
owner: saif-docgen
last_reviewed: 2026-09-15
library: SAIF.Framework.Common
reference_type: package
operation_id: OP-025
trigger: Caller needs a content fingerprint
---

# Hash a byte payload

Compute an MD5 hash of a byte payload, triggered when caller needs a content fingerprint.

| Field | Value |
| --- | --- |
| **Operation ID** | OP-025 |
| **Trigger** | Caller needs a content fingerprint |
| **Inputs** | `input` |
| **Outputs** | `Byte[]` MD5 digest |
| **Primary components** | ``ByteExtensions.GetMD5Hash(this Byte[] input)`` |
| **Entry point** | `Common/SAIF.Common/Extensions/ByteExtensions.cs` |

## Steps

1. Create an `MD5` instance inside a `using` block (`MD5.Create()`). ([BR-057](../business-rules.md#br-057-disposable-cryptographic-and-stream-resources-are-created-inside-using-blocks-so-they-are-released-deterministically))
2. Compute and return `md5.ComputeHash(input)`; the algorithm instance is disposed on scope exit. ([BR-057](../business-rules.md#br-057-disposable-cryptographic-and-stream-resources-are-created-inside-using-blocks-so-they-are-released-deterministically))

## Process flow

The following diagram visualizes this operation's control flow.

```mermaid
flowchart TD
	Start(["Caller needs a content<br>fingerprint"]) --> S1["Create MD5 instance<br>inside using block"]
	S1 --> S2["Compute md5.ComputeHash(input)"]
	S2 --> S3["Dispose MD5 instance<br>on scope exit"]
	S3 --> End([Return MD5 digest bytes])
```

## Related documentation
- [Operations and processes](../operations-processes.md)
- [Business rules](../business-rules.md)

## Sources
- `Common/SAIF.Common/Extensions/ByteExtensions.cs`