The Salted user password hashes extension derives from TYPO3 extension t3sec_saltedpw, originally developed by Marcus Krause. This extension is still available in the TYPO3 extension repository (TER) for users of TYPO3 Core 4.2.X. For a listing of contributors to the original version, please have a look at the credits chapter of t3sec_saltedpw’s extension manual.
A lot of clean up and optimization was done during core integration. A tremendous effort has been made by Steffen Ritter. Furthermore, Oliver Hader (TYPO3 Core Team), Sascha Kettler and Marcus Krause (TYPO3 Security Team) made a good amount of code contribution which allowed it to integrate the extension in TYPO3 Core.
Despite a rewrite of this extension, older passwords generated by extension t3sec_saltedpw are still compatible with this system extension.