Method and apparatus for securing electronic circuits

Abstract

A method and apparatus for protecting the stored information on an integrated circuit from being compromised through reverse engineering. To do so, the method and apparatus splits the functionality of an integrated circuit into two separate integrated circuits, which are then connected in an interlocking manner. A detection circuit monitors the interconnection of the two separate integrated circuits. Upon detection of a break in the interconnection of the two circuits, the detection circuit destroys the data stored in the two separate integrated circuits. The two integrated circuits are connected in a flip-chip fashion, thereby preventing access to the underlying conduction paths and charge storage sites which are normally used in reverse engineering an integrated circuit.

What is claimed is:  
     
         1 . A method for protecting information contained within an integrated circuit, comprising the steps of: 
 splitting the functionality of a circuit into two separate portions;    implementing the two separate portions as two separate integrated circuits;    interconnecting the two separate integrated circuits in an interlocking manner; and    monitoring an interconnection of the two separate integrated circuits.    
     
     
         2 . The method according to  claim 1 , further comprising the step of destroying the information contained within the two separate integrated circuits upon detecting a break in the interconnection of the two separate integrated circuits.  
     
     
         3 . The method according to  claim 1 , further comprising the step of interconnecting the two separate integrated circuits so that all conduction paths and charge storage sites are not accessible from the exterior.  
     
     
         4 . The method according to  claim 1 , wherein the two separate integrated circuits are connected in a flip-chip manner.  
     
     
         5 . The method according to  claim 1 , further comprising the step of writing random data to the memory upon detecting a break in the interconnection of the two separate integrated circuits.  
     
     
         6 . The method according to  claim 1 , further comprising the step of disposing at least a plurality of transistors storing sensitive information under a plurality of bond pads.  
     
     
         7 . The method according to  claim 1 , further comprising the step of disposing at least a plurality of gates storing sensitive information below a plurality of bond pads.  
     
     
         8 . An apparatus for storing information comprising: 
 a first integrated circuit having a plurality of charge storage sites in which charges are stored representing the information to be stored;    a second integrated circuit being coupled to the first integrated circuit in a flip-chip configuration and preventing access to the plurality of charge storage sites;    a detection circuit being disposed in one of the first and second integrated circuits and monitoring a connection between the first and second integrated circuits, said detection circuit altering the information stored in the first integrated circuit upon detecting a break in the connection between the first and second integrated circuits.    
     
     
         9 . The apparatus according to  claim 8 , wherein the second integrated circuit is disposed over only a portion of the first integrated circuit.  
     
     
         10 . The apparatus according to  claim 8 , wherein the first integrated circuit includes a plurality of conduction paths, and said second integrated circuit is coupled to the first integrated circuit so that the first integrated circuit covers the plurality of conduction paths.  
     
     
         11 . The apparatus according to  claim 8 , further comprising a plurality of conduction paths coupling the first integrated circuit to the second integrated circuit, wherein said detection circuit monitors conduction continuity of one or more of the plurality of conduction paths.  
     
     
         12 . The apparatus according to  claim 8 , further comprising a read-write circuit coupled to the detection circuit and the plurality of charge storage sites, said detection circuit enabling said read-write circuit to write false data to the plurality of charge storage sites upon detection of a break in continuity.  
     
     
         13 . The apparatus according to  claim 8 , further comprising an alternate power source being coupled to the detection circuit and providing power to the detection circuit upon removal of normal supply power.  
     
     
         14 . The apparatus according to  claim 13 , wherein the alternate power source also provides power to the read-write circuit upon removal of normal supply power.  
     
     
         15 . The apparatus according to  claim 13 , wherein the alternate power source provides an unsuitable voltage to the plurality of charge storage sites upon detection of a break in the continuity by the detection circuit.  
     
     
         16 . The apparatus according to  claim 13 , wherein the alternate power source includes one or more selected from the group of: a battery, a capacitor, and an energy storage device.  
     
     
         17 . The apparatus according to  claim 13 , wherein the alternate power source includes a plurality of capacitors coupled in a parallel configuration during charging, and switched to a series configuration upon detection of a continuity fault.  
     
     
         18 . An apparatus for storing information comprising: 
 a first integrated circuit having a plurality of charge storage sites in which charges are stored representing the information to be stored;    a second integrated circuit being coupled to the first integrated circuit in a flip-chip configuration and preventing access to the plurality of charge storage sites;    a proximity detection circuit being disposed in one of the first and second integrated circuits and monitoring a proximity of the first integrated circuit relative to the second integrate circuit, said proximity detection circuit altering the information stored in the first integrated circuit upon detecting a change in the proximity between the first and second integrated circuits.    
     
     
         19 . The apparatus according to  claim 18 , wherein the second integrated circuit is disposed over only a portion of the first integrated circuit.  
     
     
         20 . The apparatus according to  claim 18 , wherein the first integrated circuit includes a plurality of conduction paths, and said second integrated circuit is coupled to the first integrated circuit so that the first integrated circuit covers the plurality of conduction paths.  
     
     
         21 . The apparatus according to  claim 18 , further comprising a read-write circuit coupled to the detection circuit and the plurality of charge storage sites, said proximity detection circuit enabling said read-write circuit to write false data to the plurality of charge storage sites upon detection of a change in the proximity between the first and second integrated circuits.  
     
     
         22 . The apparatus according to  claim 18 , further comprising an alternate power source being coupled to the detection circuit and providing power to the detection circuit upon removal of normal supply power.  
     
     
         23 . The apparatus according to  claim 22 , wherein the alternate power source also provides power to the read-write circuit upon removal of normal supply power.  
     
     
         24 . The apparatus according to  claim 22 , wherein the alternate power source provides an unsuitable voltage to the plurality of charge storage sites upon detection of a change in the proximity between the first and second integrated circuits.  
     
     
         25 . The apparatus according to  claim 22 , wherein the alternate power source includes one or more selected from the group of: a battery, a capacitor, and an energy storage device.  
     
     
         26 . An apparatus for storing information in electronic form comprising: 
 a plurality of memory cells, each of which plurality of memory cells includes at least a first transistor and a second transistor, said plurality of memory cells storing the information in electronic form,    a first integrated circuit on which is disposed each of the first transistors of each of the plurality of memory cells; and    a second integrated circuit on which is disposed each of the second transistors of each of the plurality of memory cells, wherein said first and second integrated circuits are coupled together in a flip-chip configuration.    
     
     
         27 . The apparatus according to  claim 26 , further comprising a plurality of solder bonds via which the first and second transistors in each memory cell are coupled together.  
     
     
         28 . The apparatus according to  claim 27 , further comprising a continuity detection circuit monitoring a continuity of connection between the first and second integrated circuits, and writing false data to the plurality of memory cells upon detecting a break in the continuity.  
     
     
         29 . The apparatus according to  claim 26 , further comprising a first voltage supply and a second voltage supply, wherein said first voltage supply is disposed on the first integrated circuit and the second voltage supply is disposed on the second integrated circuit.  
     
     
         30 . An apparatus for storing information in electronic form comprising: 
 a plurality of memory cells, each of which plurality of memory cells includes at least a first transistor pair and a second transistor pair, said plurality of memory cells storing the information in electronic form,    a first integrated circuit on which is disposed each of the first transistor pairs of each of the plurality of memory cells; and    a second integrated circuit on which is disposed each of the second transistor pairs of each of the plurality of memory cells, wherein said first and second integrated circuits are coupled together in a flip-chip configuration.    
     
     
         31 . The apparatus according to  claim 30 , further comprising a plurality of solder bonds via which the first and second transistor pairs in each memory cell are coupled together.  
     
     
         32 . The apparatus according to  claim 30 , further comprising a continuity detection circuit monitoring a continuity of connection between the first and second integrated circuits, and writing false data to the plurality of memory cells upon detecting a break in the continuity.  
     
     
         33 . The apparatus according to  claim 30 , further comprising a first voltage supply and a second voltage supply, wherein said first voltage supply is disposed on the first integrated circuit and the second voltage supply is disposed on the second integrated circuit.  
     
     
         34 . An apparatus for storing information in electronic form comprising: 
 a plurality of memory cells, each of which plurality of memory cells includes at least a first transistor and a second transistor, said plurality of memory cells storing the information in electronic form,    a first integrated circuit on which is disposed each of the first and second transistors of each of the plurality of memory cells; and    a second integrated circuit on which is disposed a ground coupled to each of the first and second transistors, wherein the first and second transistors are coupled to the ground via the second integrated circuit, and the first and second integrated circuits are coupled together in a flip-chip configuration.    
     
     
         35 . The apparatus according to  claim 34 , further comprising a plurality of solder bonds via which the first and second transistors in each memory cell are coupled to the ground in the second integrated circuit.  
     
     
         36 . The apparatus according to  claim 34 , further comprising a continuity detection circuit monitoring a continuity of connection between the first and second integrated circuits, and writing false data to the plurality of memory cells upon detecting a break in the continuity.  
     
     
         37 . The apparatus according to  claim 34 , further comprising a first voltage supply and a second voltage supply, wherein said first and second voltage supplies are disposed on the first integrated circuit.