Look up table (LUT) based encryption with tag-based verification

A cryptographic method performed in a first chiplet, the method comprising:

• (1) receiving a message for encryption;
• (2) encrypting the message to obtain a plurality N blocks of message ciphertext, the encryption including at least one or more operations that include at least one or more XOR operations;
• (3) computing a tag on a concatenation that includes at least a nonce, the message ciphertext, and other data;
• (4) encrypting the tag to obtain said N plurality of ordered blocks of tag ciphertext, the encryption including at least one or more operations that include at least one or more XOR operations;
• (5) appending the said N plurality of ordered blocks of tag ciphertext to the said N plurality of message ciphertext blocks to obtain final ciphertext;
• and
• (6) transmitting the final ciphertext to a second chiplet;
• wherein the encrypting the message to obtain message ciphertext, the encryption including at least one or more operations that include at least one or more XOR operations comprises:
• parsing the message to obtain said N plurality of ordered message blocks;
• obtaining one or more substitute values corresponding to the said N plurality of ordered message blocks;
• obtaining, via a keystream table (KST), one or more target values associated with one or more position values, a given position value of the one or more position values being associated with a position of a given message block within the said N plurality of ordered message blocks;
• performing one or more operations that include at least one or more XOR operations to obtain said N plurality of ordered message ciphertext blocks, the one or more XOR operations being performed with at least (i) the one or more substitute values and (ii) the one or more target values;
• and
• concatenating the said N plurality of ordered blocks of message ciphertext to obtain the message ciphertext;
• and
• the obtaining one or more substitute values corresponding to the said N plurality of ordered message blocks comprises at least one of:
• obtaining the one or more substitute values from a dynamic substitution box;
• or computing the one or more substitute values as needed without accessing a dynamic substitution box.

A chiplet comprising:

• (1) a receiving circuitry configured for receiving a message for encryption;
• (2) encryption circuitry configured for encrypting the message to obtain a plurality N blocks of message ciphertext, the encryption including at least one or more operations that include at least one or more XOR operations;
• (3) tag circuitry configured for computing a tag on a concatenation that includes at least a nonce, the message ciphertext, and other data;
• (4) encryption circuitry configured for encrypting the tag to obtain said N plurality of ordered blocks of tag ciphertext, the encryption including at least one or more operations that include at least one or more XOR operations;
• (5) processing circuitry configured for appending the said N plurality of ordered blocks of tag ciphertext to said N plurality of message ciphertext blocks to obtain final ciphertext;
• and
• (6) transmitting circuitry configured for transmitting the final ciphertext to a second chiplet;
• wherein the encrypting the message to obtain message ciphertext, the encryption including at least one or more operations that include at least one or more XOR operations comprises:
• parsing the message to obtain said N plurality of ordered message blocks;
• obtaining one or more substitute values corresponding to the said N plurality of ordered message blocks;
• obtaining, via a keystream table (KST), one or more target values associated with one or more position values, a given position value of the one or more position values being associated with a position of a given message block within the said N plurality of ordered message blocks;
• performing one or more operations that include at least one or more XOR operations to obtain said N plurality of ordered message ciphertext blocks, the one or more XOR operations being performed with at least (i) the one or more substitute values and (ii) the one or more target values;
• and
• concatenating the said N plurality of ordered blocks of message ciphertext to obtain the message ciphertext;
• and
• the obtaining one or more substitute values corresponding to the said N plurality of ordered message blocks comprises at least one of:
• obtaining the one or more substitute values from a dynamic substitution box;
• or computing the one or more substitute values as needed without accessing a dynamic substitution box.