KEYRAM

KEYRAM is mainly used for key derivation after power up. It has a memory area for storing key information. There is an embedded encryption and decryption hardware sub-module in KEYRAM to protect the key information.

In security mode, random numbers are generated as masks during each boot stage in order to prevent the external exhaustive method from cracking the key information. The random number masks are stored in KEYRAM.

When the security module needs to obtain the key from the KEYRAM through the key port bus, the KEYRAM embedded sub-module will automatically decrypt and import the key with the confusion of the random number mask into the security module. In addition, the security module also needs to load the random number mask so as to recovery the plain key.