Use uma senha mestra :
Firefox: "Tools -> Options -> Security / Passwords -> Use a master password"
É editável através do seguinte processo:
Firefox: "Tools -> Options -> Security / Passwords -> Change Master Password"
Caso contrário, se for um dispositivo SmartCard, a API webCrypto pode ser o que você está procurando:
Warning: The features mentioned in this article are proprietary Mozilla extensions, and are not supported in any other browser.
Além disso, as Ferramentas NSS podem ser o que você procura :
Software developed by the Mozilla.org projects traditionally used its own implementation of security protocols and cryptographic algorithms, originally called Netscape Security Services, nowadays called Network Security Services (NSS). NSS is a library written in the C programming language. It's free and open source software, and many other software projects have decided to use it. In order to support multiple operating systems (OS), it is based on a cross platform portability layer, called the Netscape Portable Runtime (NSPR), which provides cross platform application programming interfaces (APIs) for OS specific APIs like file system access, memory management, network communication, and multithreaded programming.