Patent attributes
Apparatus and methods for implementing software protection using code overlapping are disclosed. In one implementation, a combination block comprising a first sub-block of instructions with one or more interspersed obfuscation instructions is received. The obfuscation instructions interspersed among sequentially executable instructions of the first sub-block of instructions can include instructions from other sub-blocks as well as control instructions configured to guide a processor to execute all of the instructions in first sub-block of instructions in sequence. The obfuscation instructions are replaced with one or more replacement instructions. The replacement instructions can be of a same bit-length as the replaced obfuscation instructions. Moreover, the replacement instructions can include integrity checks configured to check for tampering with instructions and/or runtime program state in the first sub-block and/or the combination block.
