A ZUC operation produces a keystream in 32-bit data blocks as defined by ETSI/SAGE “Specification of the 3GPP Confidentiality and Integrity Algorithms 128-EEA3 & 128-EIA3. Document 2: ZUC Specification” Version: 1.6.
A EEA3/EIA3 (-E3) option includes operation per ETSI/SAGE “Specification of the 3GPP Confidentiality and Integrity Algorithms EEA3 & EIA3. Document 1: EEA3 and EIA3 Specification”. The input data shall be zero-padded to 64 bits.
A rising input on the START port triggers the beginning of a cryptographic operation, using the KEY and IV inputs to initialize the keystream. The core then starts to output the keystream per ZUC algorithm..
When all the rounds are completed, the READY signal is raised and the next unit of keystream is available on the output Q.
The core continues to produce the keystream as long as START is kept high. To throttle the output, at any time the CEN input can be brought low to pause the core.
A cryptographic operation can be aborted at any time by lowering the START signal for at least one clock cycle.
With the -E3 option, the core performs the encryption and authentication using the EEA3 and EIA3 algorithms. The input data shall be zero-padded to D/Q bus width. LAST input shall be asserted along with the last word of the input data. After calculating the MAC, the core will assert the DONE output and output the calculated MAC value onto the MAC[31:0] bus.