> For the complete documentation index, see [llms.txt](https://aaronice.gitbook.io/system-design/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://aaronice.gitbook.io/system-design/architecture-toolbox/encoding-decoding-encryption-decryption.md).

# Encoding Decoding Encryption Decryption

## Base64

[Base 64](http://en.wikipedia.org/wiki/Base64) encoding is generally used to transmit binary data over a mechanism that only allows ASCII text.

## MD5

[MD5 is not considered a strong encryption mechanism](http://www.kb.cert.org/vuls/id/836068). SHA-1 would be better suited for this task.

## SHA1 / SHA-256