# Heterogeneous Hardware and Software

In a typical 3-of-5 setup, we use **at least three different hardware/software platforms** at one time - such as Trezor, Ledger, and a mobile phone (iOS or Android). Neither software nor hardware wallets are perfect. From time to time a vulnerability is discovered in one brand. Relying on multiple brands and types of wallets prevents a vulnerability in one brand from compromising the overall storage system.

This also protects against supply chain attacks. If a malicious actor were to infiltrate and tamper with the devices produced by any one supplier, it would not be enough to compromise our clients' funds.

For the complete documentation index, see [llms.txt](https://docs.casa.io/wealth-security-protocol/llms.txt). This page is also available as [Markdown](https://docs.casa.io/wealth-security-protocol/chosen-features/heterogeneous-hardware-and-software.md).