Low cost cryptographic accelerator
A low-cost cryptographic accelerator is disclosed that accelerates inner loops of a cryptographic process. The cryptographic accelerator performs operations on cryptographic data provided by a central processing unit (CPU) running a software cryptographic process to create a combined hardware and software cryptographic process, resulting in a lower cost secure communication solution than software-only or hardware-only cryptographic processes. In an embodiment, a cryptographic accelerator comprises: an interface configured to receive cryptographic data, the cryptographic data indicating a particular cryptographic process to be performed on the cryptographic data; transformation logic configured to perform a cryptographic operation on the cryptographic data according to the cryptographic process, the transformation logic including logic for performing cryptographic operations for a plurality of different cryptographic processes; and a state register configured for storing a result of the cryptographic operation.
1. A system comprising:
a central processing unit (CPU);
memory storing instructions that, when executed by the CPU, cause the CPU to perform operations comprising:
sending cryptographic data to an aliased register of a hardware accelerator, wherein a first address used to send the cryptographic data to the aliased register is indicative of a first operation of a cryptographic process;
receiving, from the hardware accelerator, first transformed cryptographic data obtained responsive to performing a first operation of the cryptographic process on the cryptographic data, the first operation comprising one of a first cryptographic encryption operation or a first cryptographic decryption operation;
sending the cryptographic data to the aliased register of the hardware accelerator, wherein a second address used to send the cryptographic data to the aliased register is indicative of a second operation of the cryptographic process; and
receiving, from the hardware accelerator, second transformed cryptographic data obtained responsive to performing the second operation of the cryptographic process on the cryptographic data, the second operation comprising one of a second cryptographic encryption operation or a second cryptographic decryption operation that are different than the first cryptographic encryption operation and the first cryptographic decryption operation, respectively,
wherein the first operation and the second operation are performed sequentially or are performed in parallel.
2. The system of claim 1 , wherein the cryptographic process is from a group of cryptographic processes comprising: Advanced Encryption Standard (AES), Secure Hash Algorithm (SHA) or Galois Counter Mode (GCM).
3. The system of claim 1 , wherein the second address indicates the second operation according to an aliased register map.
4. The system of claim 1 , wherein state vectors and control flow are contained in the CPU.
5. The system of claim 1 , wherein the cryptographic process is Advanced Encryption Standard (AES), and the second operation includes calculating round keys using a key schedule.
6. The system of claim 1 , wherein the cryptographic process is Advanced Encryption Standard (AES) and the second operation comprises one of: SubBytes, Inverse SubBytes, ShiftRows, Inverse ShiftRows, MixColumn or Inverse MixColumn operation.
7. The system of claim 1 , wherein the cryptographic process is Secure Hash Algorithm (SHA) and the second operation comprises one of: Message Expansion loop or Compression Function loop.
8. The system of claim 1 , wherein the cryptographic process is Galois Counter Mode (GCM) and the second operation comprises a finite field multiplication with a 128-bit polynomial.
9. The system of claim 1 , wherein sending the cryptographic data to the aliased register of the hardware accelerator further comprises:
initiating a write of the cryptographic data from a CPU register to a state register of the hardware accelerator.
10. The system of claim 9 , wherein the second transformed cryptographic data is available at the state register upon completing a write cycle corresponding to the write operation.
11. The system of claim 1 , wherein performing the first operation of the cryptographic process on the cryptographic data comprises: performing the first operation of the cryptographic process on a first portion of the cryptographic data.
12. The system of claim 11 , wherein performing the second operation of the cryptographic process on the cryptographic data comprises: performing the second operation of the cryptographic process on the first portion of the cryptographic data.
13. The system of claim 11 , wherein performing the second operation of the cryptographic process on the cryptographic data comprises: performing the second operation of the cryptographic process on a processed portion of the cryptographic data obtained responsive to performing the first operation of the cryptographic process on the first portion of the cryptographic data.
14. A system comprising:
a central processing unit (CPU);
memory storing instructions that, when executed by the CPU, cause the CPU to perform operations of a cryptographic process on cryptographic data, the operations comprising:
sending a first portion of the cryptographic data to an aliased register of a hardware accelerator using one or more addresses;
receiving, from the hardware accelerator, a first transformed cryptographic data obtained responsive to performing one or more operations of the cryptographic process on the first portion of the cryptographic data;
sending a second portion of the cryptographic data to the aliased register of the hardware accelerator using the one or more addresses; and
receiving, from the hardware accelerator, a second transformed cryptographic data obtained responsive to performing the one or more operations of the cryptographic process on the second portion of the cryptographic data,
wherein the one or more addresses used to send the first and second portions of the cryptographic data to the aliased register indicate the one or more of the operations of the cryptographic process.