StreamSec Tools 2.x is the original branch of the StreamSec Tools cryptographic library for Borland Delphi, later CodeGear Delphi and now Embarcadero Delphi ^TM. Delphi 2007 and up are supported by the current branch.

StreamSec Tools 2.x was designed as a largely independent cryptographic library, based on clean-room implementations of all supported protocols, schemes and algorithms, with no dependency on other cryptoghraphic libraries such as OpenSSL or Windows CryptoAPI. The rationale behind this design was to minimize the impact of security flaws found in other implementations, and to ensure that the set of cryptographic functionality available to the application did not depend on the Windows version or Windows edition to which the software was deployed.

StreamSec Tools 2.x is still actively maintained and updated, due to it's widespread use as a SSL/TLS solution for e.g. RealThinClient SDK, NexusDB, kbmMW, Indy and Ararat Synapse.

StreamSec Tools 2.x is currently at major version 2.3. Developers who still use StreamSec Tools 2.1 are encouraged to update, since major version 2.1 is no longer maintained. Major version 2.2 or higher is also required for compatibility with the Win64 compiler. PKC Tools 4.0 is a required add-on for Win64 support.