Base64 Is Not Encryption: Visually Confirming Reversibility with PowerShell

About This Article
This article was created using an automated generation workflow leveraging generative AI. It reviews .NET's Base64 conversion APIs and organizes them so you can observe encoding and restoration using only dummy strings.

Verification Status: 📘 Confirmed with official .NET specifications, hardware testing not performed

Base64 is anencodingscheme that makes data easier to transport as strings. Because it can be reversed without a key, it does not substitute for encryption, which protects confidentiality.

Try It First

$text = 'papanda-demo'
$b64 = [Convert]::ToBase64String([Text.Encoding]::UTF8.GetBytes($text))
$b64
[Text.Encoding]::UTF8.GetString([Convert]::FromBase64String($b64))

Look Here

The appearance of the second line changes, but if papanda-demo is successfully restored at the end, it works. Since passwords can be restored in the same way, simply converting them to Base64 does not make them secure.

Change One Part

papanda-demo Change パンダ to

Why It Works

Base64 is a representation format that maps 3 bytes to the equivalent of 4 characters. No decryption key exists, and anyone who knows the conversion rules can reverse it.

graph LR
A[文字列] --> B[UTF-8 bytes]
B --> C[Base64]
C --> D[bytesへ復元]
D --> E[元の文字列]

Practical Application

It is useful for representing binary data in places where it is difficult to handle directly, such as in emails or JSON. On the other hand, do not refer to putting tokens or passwords into configuration files as Base64 "encryption." To protect secrets, use OS credential stores, secret management services, or appropriate encryption methods.

Microsoft .NET Convert.ToBase64String: https://learn.microsoft.com/dotnet/api/system.convert.tobase64string

Microsoft .NET Convert.FromBase64String: https://learn.microsoft.com/dotnet/api/system.convert.frombase64string