High Throughput AES

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High Throughput AES

• Alireza Hodjat
• IVGroup

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The AES Algorithm
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Outer-round Pipelining
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Inner- and Outer-round Pipelining
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The Highest Possible Throughput

• The choice of 128-bit key only
• Completely unrolled loop
• Pipelined
• Between each round (Outer-round)
• Inside each round (Inner-round)
• This causes huge area consumption.

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Area Optimization

• Area optimization inside each round
• Two different techniques
• Resource sharing
• Re-timing
• Break the critical path and perform the algorithm
  in multiple clock cycles
• Critical path Substitution
• Area-delay trade-off

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Sbox Area-Delay Trade-off

• Direct Implementation Look-up table
• Indirect Implementation GF(24)
• Wolkerstorfer Design
• Patricks codes

 
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AES Encrypt Datapath
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Key Scheduling Datapath
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Design 1 Straight Forward
1 Round
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Design 2 Use re-timing for Sbox
1 Round
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Design 3 Use resource sharing
1 Round
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Design 4 Use resource sharing and re-timing
for Sbox
5 Cycle
1 Round
5 Cycle
5 Cycle
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Design 5 Resource sharing and pipelining and
re-timing for Sbox
1 Round
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Inner-Round Pipeline for Design 5
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Performance Estimation