Pre-shared key

With Pre-Shared Key ( " pre-agreed key " ) or short- PSK is referred to such encryption methods in which the key must be known to both parties prior to the communication, ie symmetric methods. PSK encryption has the advantage that it is much easier to realize between two subscribers known as asymmetric encryption. The major disadvantage of the method is that both participants have to change the key before the actual communication in secret. It follows that the PSK method for many applications in the Internet (such as online shopping ) is not suitable since the previous key exchange in this case is not possible or too expensive. In such a case, it is better to use the public-key method.

The term is often associated with PSC Wireless LAN connection because often the encryption method WPA -PSK is used in wireless networks. For small networks, such as in the home this is a good method because the key can be easily entered from one person to the various devices such as routers and PC.

As reported heise online, the maker of security software Elcomsoft was announced in October 2008 that can be WPA -PSK keys under parallel using multiple Nvidia graphics cards " relatively quickly " to restore.