at88sc018 ATMEL Corporation, at88sc018 Datasheet - Page 21

• Manufacturer Part Number: at88sc018
• Description: Cryptocompanion? Chip For Cryptomemory And Cryptorf
• Manufacturer: ATMEL Corporation

3.10.
3.11.
5277C–CryptoCompanion–9/09
Table 31.
Table 32.
GetRandom
The AT88SC018 generates a 20 byte random number using its internal high quality random number generator and
outputs this value. There is no restriction on the system as to where these random numbers may be used – their
cryptographic quality makes them suitable for any operation on the system in addition to the CRF operations.
When the AT88SC018 is unlocked, the random numbers generated will follow a predictable pattern based on the state
of the RNGSeed EEPROM value and the number of power cycles since this seed has been written. This mechanism
facilitates testing.
Table 33.
Table 34.
IncrementCounter
Increment the value of the specified counter by 1.
Table 35.
Table 36.
Size
Data
Data
Data
Counter
Name
Name
Name
Name
Name
Name
Inputs
Outputs
Inputs
Outputs
Inputs
Outputs
Size
Size
Size
Size
Size
Size
20
⎯
⎯
1
1
One less than the number of bytes to be sent through crypto engine. If this byte is 0 grind
1 byte, if 0x13 grind 20 bytes. If ≥ 0x14, return BadCmd.
Crypto engine input bytes, maximum 20.
Crypto engine output bytes, maximum 20.
Random bytes from the RNG
Counter index to be incremented, must be from 0-3. The upper 4 bits of this parameter are
ignored.
Description
Description
Description
Description
Description
Description
CryptoCompanion Chip
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