AT88SC0104C datasheet(16/58 Pages) ATMEL

16 / 58 page

5210B–SMIC–11/08

AT88SC0104/0204/0404/0808/1616/3216/6416/12816/25616C

Communication Security Modes

Communication between the device and host operates in three basic modes: Standard, Authen-

tication and Encryption Modes. The Standard Mode is the default mode for the device after

power-up. Special procedures exist for enabling Authentication and Encryption Modes but are

beyond the scope of this document. Information pertaining to use of Authentication and Encryp-

tion Modes of CryptoMemory is available from Atmel under Non-Disclosure and/or Limited

Licensing Agreements (NDA and/or LLA).

5.1

Security Operations

5.1.1

Password Verification

The use of passwords protects read and write accesses to the user zones. Any one of 8 pass-

word sets is available for assignment to any user zone through configuration of access registers.

CryptoMemory provides separate 24-bit passwords for read and write operations. Read pass-

words grant only read accesses to zones under password protection, while write passwords

grant both read and write accesses. Successful presentation of any password renders the verify

password command active until the presentation of another password or device reset. Only one

password may be active at a time. Presenting incorrect passwords decrements the value of the

corresponding password attempts counter (PAC). Decrementing the PAC to $00 permanently

disables the corresponding password and permanently renders the corresponding user zone(s)

under protection inaccessible. Operation in authentication or encryption modes requires encryp-

tion of passwords for all password transactions.

Figure 5-1.

Password Verification

5.1.2

Mutual Authentication

The mutual authentication mode employs cryptographic technology that allows the device to

authenticate the host, and the host to authenticate the device prior to any data communication

between the two. Additional information on using mutual authentication is available from Atmel

under NDA and/or LLA.

Table 5-1.

Communication Security Modes

Mode

Configuration Data

User Data

Passwords

Data Integrity Check

Standard/Password

clear

n/a

Authentication

clear

encrypted

MAC

Encryption

clear

encrypted

MAC

Configuration data includes the entire configuration memory except the passwords.

MAC: Message Authentication Code.

CryptoMemory Device

Allow Access

Command/Communication

Host Logic

Verify Password

Send Password

encrypted if performed

after Mutual Authentication

AT88SC0104C Datasheet(PDF) 16 Page - ATMEL Corporation

AT88SC0104C Datasheet(HTML) 16 Page - ATMEL Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58

Datasheet Download

Link URL