Just-in-time post-quantum cryptography (PQC) key expansion

A post-quantum cryptography (PQC) key expander, comprising:

• a first counter configured to output a first index value;
• a second counter configured to output a second index value;
• and
• accelerator circuitry configured to perform a key expansion function using a seed value by sequentially generating data fragments of an expanded key, the seed value being identified with a portion of a cryptographic key, and the expanded key being associated with a matrix having a plurality of entries, each one of the plurality of entries being identified with a polynomial value,
• wherein a combination of the first and the second index values indicate, to the accelerator circuitry, a next one of the data fragments of the expanded key that is to be generated,
• wherein the expanded key is used to perform at least part of a cryptographic-based function,
• wherein the first index value comprises a row index identified with the plurality of entries of the matrix, and
• wherein the second index value comprises a column index identified with the plurality of entries of the matrix.

A post-quantum cryptography (PQC) hardware accelerator, comprising:

• accelerator circuitry configured to perform a key expansion function using a seed value by sequentially generating data fragments of an expanded key, the seed value being identified with a portion of a cryptographic key, and the expanded key being associated with a matrix having a plurality of entries, each one of the plurality of entries being identified with a polynomial value;
• a first counter configured to increment a row index of the matrix;
• a second counter configured to increment a column index of the matrix,
• wherein a combination of the column and the row indices indicate, to the accelerator circuitry, a next one of the plurality of entries of the matrix to generate a respective data fragment of the expanded key;
• a memory configured to store the sequentially generated data fragments;
• and
• processing circuitry configured to perform a cryptographic-based function using the expanded key based upon an iterative aggregation of the sequentially generated data fragments.

A post-quantum cryptography (PQC) key expander, comprising:

• a first counter configured to output a first index value;
• a second counter configured to output a second index value;
• and
• accelerator circuitry configured to perform a key expansion function using a seed value by sequentially generating data fragments of an expanded key, the seed value being identified with a portion of a cryptographic key, and the expanded key being associated with a matrix having a plurality of entries, each one of the plurality of entries being identified with a polynomial value,
• wherein a combination of the first and the second index values indicate, to the accelerator circuitry, a next one of the data fragments of the expanded key that is to be generated,
• wherein the expanded key is used to perform at least part of a cryptographic-based function, and
• wherein the first and the second counter is each configured, upon the accelerator circuitry completing each sequentially generated data fragment of the expanded key, to selectively increment the first index value and the second index value, respectively, to indicate to the accelerator circuitry a next one of the plurality of entries of the matrix to generate a respective data fragment of the expanded key.