Chih-Pin Su

A high-throughput low-cost AES processor

We propose an efficient hardware implementation of the advanced encryption standard algorithm, with key expansion capability. Compared to the widely used table lookup technique, the proposed basis transformation technique reduces the hardware overhead of the S-box by 64 percent. Our pipelined design has a very high throughput rate. Using typical 0.35 μm CMOS technology, a 200 MHz clock is easily achieved, and the throughput rate in the non-feedback cipher mode is 2.38 Gb/s for 128-bit keys, 2.008 Gb/s for 192-bit keys, and 1.74 Gb/s for 256-bit keys, respectively. Testability of the design is also considered. The hardware cost of the AES design is approximately 58 K gates using a standard synthesis flow.

Single- and Multi-core Configurable AES Architectures for Flexible Security

As networking technology advances, the gap between network bandwidth and network processing power widens. Information security issues add to the need for developing high-performance network processing hardware, particularly that for real-time processing of cryptographic algorithms. This paper presents a configurable architecture for Advanced Encryption Standard (AES) encryption, whose major building blocks are a group of AES processors. Each AES processor provides 219 block cipher schemes with a novel on-the-fly key expansion design for the original AES algorithm and an extended AES algorithm. In this multicore architecture, the memory controller of each AES processor is designed for the maximum overlapping between data transfer and encryption, reducing interrupt handling load of the host processor. This design can be applied to high-speed systems since its independent data paths greatly reduces the input/output bandwidth problem. A test chip has been fabricated for the AES architecture, using a standard 0.25-¿m CMOS process. It has a silicon area of 6.29 mm2, containing about 200,500 logic gates, and runs at a 66-MHz clock. In electronic codebook (ECB) and cipher-block chaining (CBC) cipher modes, the throughput rates are 844.9, 704, and 603.4 Mb/s for 128-, 192-, and 256-b keys, respectively. In order to achieve 1-Gb/s throughput (including overhead) at the worst case, we design a multicore architecture containing three AES processors with 0.18-¿m CMOS process. The throughput rate of the architecture is between 1.29 and 3.75 Gb/s at 102 MHz. The architecture performs encryption and decryption of large data with 128-b key in CBC mode using on-the-fly key generation and composite field S-box, making it more cost effective (with better thousand-gate/gigabit-per-second ratio) than conventional methods.

An HMAC processor with integrated SHA-1 and MD5 algorithms

Cryptographic algorithms are prevalent and important in digital communications and storage, e.g., both SHA-1 and MD5 algorithms are widely used hash functions in IPSec and SSL for checking the data integrity. In this paper, we propose a hardware architecture for the standard HMAC function that supports both. Our HMAC design automatically generates the padding words and reuses the key for consecutive HMAC jobs that use the same key. We have also implemented the HMAC design in silicon. Compared with existing designs, our HMAC processor has lower hardware cost---12.5% by sharing of the SHA-1 and MD5 circuitry and a little performance penalty.

A high-throughput low-cost AES cipher chip

We propose an efficient hardware implementation of the AES (Advanced Encryption Standard) algorithm, with key expansion capability. Compared with the widely used table-lookup technique, the proposed basis transformation technique reduces the hardware overhead of the S-box by 64%. Our pipelined design has a very high throughput rate. Using a typical 0.35 /spl mu/m CMOS technology, a 200 MHz clock is easily achieved, and the throughput rate is 2.381 Gbps for 128-bit keys, 2.008 Gbps for 192-bit keys, and 1.736 Gbps for 256-bit keys. Testability of the design also is considered. The hardware cost of the AES design is about 58.5 K gates.

A configurable AES processor for enhanced security

We propose a configurable AES processor for extended-security communication. The proposed architecture can provide up to 2/sup 19/ different AES block cipher schemes within a reasonable hardware cost. Data can be encrypted not only with secret keys and initial vectors, but also by different block ciphers during the communication. A novel on-the-fly key expansion design is also proposed for 28-, 192-, and 256-bit keys. Our unified hardware can run both the original AES algorithm and the extended AES algorithm. The proposed processor design has been fabricated by a 0.25/spl mu/m CMOS process, with a silicon area of 6.93mm/sup 2/ - about 200.5K equivalent gates. Under a 66MHz clock, the throughput rate for both the ECB and CBC operation modes are 844.8Mbps, 704Mbps, and 603.4Mbps for 128-bit, 192-bit, and 256-bit keys, respectively.

Design of a scalable RSA and ECC crypto-processor

In this paper, we propose a scalable word-based crypto-processor that performs modular multiplication based on modified Montgomery algorithm for finite fields GF(P) and GF(2m). The unified crypto-processor supports scalable keys of length up to 2048 bits for RSA and 512 bits for elliptic curve cryptography (ECC). Further extension of the key length can be done easily by enlarging the memory module or using the external memory resource. With the proposed parity prediction technique, our pipelined crypto-processor achieves a 512-bit RSA encryption ratè of 276 Kbps and a 160-bit ECC encryption rate of 73.3 Kbps for a 220MHz clock rate.

A word-based RSA crypto-processor with enhanced pipeline performance

We propose a high speed RSA crypto-processor based on an enhanced word-based Montgomery Multiplication (MM) algorithm. With the help of the proposed Correction Module (CM), the word-based modular multiplier can achieve 100% utilization. A simplified Parity Prediction Module (PPM) is also proposed to eliminate the pipeline stall. Using a 0.18 /spl mu/m CMOS standard cell library, our RSA crypto-processor achieves a 512-bit RSA encryption rate of 375Kbps under 300MHz clock. The result shows that our architecture is cost-effective in terms of area and performance.

A highly efficient AES cipher chip

We present an efficient hardware implementation of the AES (Advanced Encryption Standard) algorithm, with key expansion capability. Instead of the widely used table-lookup implementation of S-box, the proposed basis transformation technique reduces the hardware overhead of the S-box by 64% and is easily pipelined to achieve high throughput rate. Using a typical 0.25μm CMOS technology, the throughput rate is 2.977 Gbps for 128-bit keys, 2.510 Gbps for 192-bit keys, and 2.169 Gbps for 256-bit keys with a 250MHz clock. Testability of the design is also considered. The area of the core circuit is about 1,279 x 1,271μm2.

Design and test of a scalable security processor

This paper presents a security processor to accelerate cryptographic processing in modern security applications. Our security processor is capable of popular cryptographic functions such as RSA, AES, hashing and random number generation, etc. With proposed crypto-DMA controller, data gathering and scattering become flexible for security processing, using a simple descriptor-based programming model. The architecture of the security processor with its core-based platform is scalable and configurable for security variations in performance, cost and power consumption. Different number of data channels and crypto-engines can be used to meet the specifications. In addition, a DFT platform is also implemented for the design-test integration. The security processor has been fabricated with 0.18/spl mu/m CMOS technology. The core area is 3.899mm /spl times/ 2.296mm (525K gates approximately) and the operating clock rate is 83MHz.