The document discusses light-weight cryptography for embedded systems and sensor networks. It presents several light-weight block ciphers, stream ciphers, hashes, and asymmetric encryption methods that have low power, chip size, and timing requirements. It specifically describes the Rabbit stream cipher, which only needs 512 bits of storage and uses eight counters and states that are rotated and XORed with an initialization vector and key to generate a 128-bit key stream for encryption.

1. Light-Weight Crypto:
Rabbit
Prof Bill Buchanan, The Cyber Academy
http://asecuritysite.com

2. Light-weight crypto
• Conventional cryptography. Servers and Desktops. Tablets and smart
phones.
• Light-weight cryptography. Embedded Systems. RFID and Sensor
Networks.
• Light-weight cryptography the main constraints that we have are typically
related to:
• Power requirements.
• Gate equivalents (GEs). Chip size: µm2.
• Timing.

3. Light-weight crypto
• Block: XTEA. PRESENT. SIMON. SPECK. CLEFIA. LED.
• Stream: Enocoro. Grain. Trivium. Mickey. Rabbit.
• Hash: SPONGENT. Lesamnta-LW. QUARK. PHOTON.
• Asymmetric. ELLI. ELLI. ELLI is a light-weight asymmetric encryption
method.
• MAC. Chaskey (MAC).
Link.

4. AES

5. Rabbit Stream Cipher

6. Rabbit Stream Cipher
• Rabbit only needs 512 bits of storage
space for the current state.
• Eight counters (c0 —c7)
• Eight states (x0 —x7),
• and where the state number is defined as
i.
• Initially the key is loaded in the ci and xi
registers.
• Next the IV value is applied with an EX-OR
function to the ci registers. After the
initialization, each iteration performs
after rotate left operations (<<<) on the
state values.
• The x values are then used to create eight
state values, and which builds a 128-bit
key stream block for each iteration of i.
The 128-bit key stream block is then used
to EX-OR with the data stream.

7. Rabbit Stream Cipher
Message: abc
IV: 0
Encryption password: qwerty
Encryption key: d8578edf8458ce06fbc5bb76a58c5ca4
======Rabbit encryption========
Encrypted: 314a77
Decrypted: abc
Link

8. Rabbit Stream Cipher

9. Light-Weight Crypto:
Rabbit
Prof Bill Buchanan, The Cyber Academy
http://asecuritysite.com