Mixed sequencing of polynomial-diverse encryption and decryption operations for side channel attack protection

1. A system on a chip (SoC) comprising:

an encryption/decryption engine configured to:

encrypt transmission (Tx) channel data using an encryption operation set configured with a first polynomial; and

decrypt encrypted received (Rx) channel data using a decryption operation set configured with a second polynomial that is different from the first polynomial; and

a security processor configured to:

select a pairing of the first polynomial and the second polynomial based on a determination that a first power profile associated with the first polynomial differs by at least a threshold power profile differential from a second power profile associated with the second polynomial;

multiplex the encryption operation set against the decryption operation set with a varied sequence of selection inputs on a round-by-round basis to generate a mixed sequence of encryption rounds and decryption rounds; and

control the encryption/decryption engine to encrypt the Tx channel data and decrypt the encrypted Rx channel data in a combined data path according to the mixed sequence of encryption rounds and decryption rounds.

2. The SoC of claim 1 , wherein the security processor is configured to generate the varied sequence of selection inputs as one of a random sequence, a pseudo-random sequence, or a deterministic sequence.

3. The SoC of claim 1 , wherein the security processor is configured to generate the varied sequence of selection inputs as a non-static sequence.

4. The SoC of claim 1 ,

wherein the first polynomial comprises a first ground-field polynomial and a first extension-field polynomial,

wherein the second polynomial comprises a second ground-field polynomial and a second extension-field polynomial,

wherein the encryption/decryption engine applies the first ground-field polynomial to split 8-bit data blocks of the Rx channel data into respective 4-bit Rx channel data segments,

wherein the encryption/decryption engine applies the second ground-field polynomial to split 8-bit data blocks of the Tx channel data into respective 4-bit Tx channel data segments,

wherein the encryption/decryption engine applies the first extension-field polynomial to encrypt a first subset of the 4-bit data segments, and

wherein the encryption/decryption engine applies the second extension-field polynomial to decrypt a second subset of the 4-bit data segments.

5. The SoC of claim 4 , wherein the security processor is further configured to execute a scripting agent to explore a pool of mappings that include a first mapping of the first ground-field polynomial to the first extension-field polynomial and a second mapping of the second ground-field polynomial to the second extension-field polynomial to select the first polynomial and the second polynomial.

6. The SoC of claim 1 , wherein the encryption/decryption engine is further configured to:

execute a byte substitution computational stage of the encryption operation set using finite-field byte substitution; and

execute an inverse byte substitution computational stage of the decryption operation set using finite-field inverse byte substitution.

7. The SoC of claim 1 , wherein the SoC is integrated into one of a head-mounted device (HMD) of an artificial reality system or a peripheral device of the artificial reality system.

8. A head-mounted device (HMD) comprising:

a system on a chip (SoC) comprising:

an encryption/decryption engine configured to:

encrypt transmission (Tx) channel data using an encryption operation set configured with a first polynomial; and

decrypt encrypted received (Rx) channel data using a decryption operation set configured with a second polynomial that is different from the first polynomial; and

a security processor configured to:

select a pairing of the first polynomial and the second polynomial based on a determination that a first power profile associated with the first polynomial differs by at least a threshold power profile differential from a second power profile associated with the second polynomial;

multiplex the encryption operation set against the decryption operation set with a varied sequence of selection inputs on a round-by-round basis to generate a mixed sequence of encryption rounds and decryption rounds; and

control the encryption/decryption engine to encrypt the Tx channel data and decrypt the encrypted Rx channel data in a combined datapath according to the mixed sequence of encryption rounds and decryption rounds; and

an interface coupled to the SoC, the interface being configured to:

transmit the Tx traffic; and

receive the encrypted Rx traffic.

9. The HMD of claim 8 , wherein the security processor is configured to generate the varied sequence of selection inputs as one of a random sequence, a pseudo-random sequence, or a deterministic sequence.

10. The HMD of claim 8 , wherein the security processor is configured to generate the varied sequence of selection inputs as a non-static sequence.

11. The HMD of claim 8 ,

wherein the first polynomial comprises a first ground-field polynomial and a first extension-field polynomial,

wherein the second polynomial comprises a second ground-field polynomial and a second extension-field polynomial,

wherein the encryption/decryption engine applies the first ground-field polynomial to split 8-bit data blocks of the Rx channel data into respective 4-bit Rx channel data segments,

wherein the encryption/decryption engine applies the second ground-field polynomial to split 8-bit data blocks of the Tx channel data into respective 4-bit Tx channel data segments,

wherein the encryption/decryption engine applies the first extension-field polynomial to encrypt a first subset of the 4-bit data segments, and

wherein the encryption/decryption engine applies the second extension-field polynomial to decrypt a second subset of the 4-bit data segments.

12. The HMD of claim 11 , wherein the security processor is further configured to execute a scripting agent to explore a pool of mappings that include a first mapping of the first ground-field polynomial to the first extension-field polynomial and a second mapping of the second ground-field polynomial to the second extension-field polynomial to select the first polynomial and the second polynomial.

13. The HMD of claim 8 , wherein a encryption/decryption engine is further configured to:

execute a byte substitution computational stage of the encryption operation set using finite-field byte substitution; and

execute an inverse byte substitution computational stage of the decryption operation set using finite-field inverse byte substitution.

14. A peripheral device comprising:

a system on a chip (SoC) comprising:

an encryption/decryption engine configured to:

encrypt transmission (Tx) channel data using an encryption operation set configured with a first polynomial; and

decrypt encrypted received (Rx) channel data using a decryption operation set configured with a second polynomial that is different from the first polynomial; and

a security processor configured to:

select a pairing of the first polynomial and the second polynomial based on a determination that a first power profile associated with the first polynomial differs by at least a threshold power profile differential from a second power profile associated with the second polynomial;

multiplex the encryption operation set against the decryption operation set with a varied sequence of selection inputs on a round-by-round basis to generate a mixed sequence of encryption rounds and decryption rounds; and

control the encryption/decryption engine to encrypt the Tx channel data and decrypt the encrypted Rx channel data in a combined data path according to the mixed sequence of encryption rounds and decryption rounds; and

an interface coupled to the SoC, the interface being configured to:

transmit the Tx traffic; and

receive the encrypted Rx traffic.

15. The peripheral device of claim 14 , wherein the security processor is configured to generate the varied sequence of selection inputs as one of a random sequence, a pseudo-random sequence, or a deterministic sequence.

16. The peripheral device of claim 15 , wherein the security processor is configured to generate the varied sequence of selection inputs as a non-static sequence.

17. The peripheral device of claim 14 ,

wherein the first polynomial comprises a first ground-field polynomial and a first extension-field polynomial,

wherein the second polynomial comprises a second ground-field polynomial and a second extension-field polynomial,

wherein the encryption/decryption engine applies the first ground-field polynomial to split 8-bit data blocks of the Rx channel data into respective 4-bit Rx channel data segments,

wherein the encryption/decryption engine applies the second ground-field polynomial to split 8-bit data blocks of the Tx channel data into respective 4-bit Tx channel data segments,

wherein the encryption/decryption engine applies the first extension-field polynomial to encrypt a first subset of the 4-bit data segments, and

wherein the encryption/decryption engine applies the second extension-field polynomial to decrypt a second subset of the 4-bit data segments.

18. The peripheral device of claim 11 , wherein the security processor is further configured to execute a scripting agent to explore a pool of mappings that include a first mapping of the first ground-field polynomial to the first extension-field polynomial and a second mapping of the second ground-field polynomial to the second extension-field polynomial to select the first polynomial and the second polynomial.

19. The peripheral device of claim 14 , wherein the encryption/decryption engine is further configured to:

execute a byte substitution computational stage of the encryption operation set using finite-field byte substitution; and

execute an inverse byte substitution computational stage of the decryption operation set using finite-field inverse byte substitution.