Patent ID: 8826377

Claim:
An authentication method employed by a portable electronic device, comprising: generating first data; deriving reference data according to the first data; receiving second data from a host computer; and determining whether the host computer is permitted to access data stored in the portable electronic device according to the reference data and the second data; wherein the step of deriving reference data according to the first data comprises: generating seed data by using formula InSeed ′ ⁡ [ i ] = InData [ i ⁢ << C ⁢ 1 + C ⁢ ⁢ 2 ⁢ + ( ∑ k = i ⁢ << C ⁢ 1 ( i ⁢ << C ⁢ ⁢ 1 ) + C ⁢ ⁢ 2 ⁢ ⁢ InData ⁡ [ k ] ) ⁢ Mod ( C ⁢ 2 ) ] , wherein InSeed′[i] is the seed data, InData[ ] is the first data, C1 is a constant, C2 is a number of bytes of the seed data, and i=0, 1, 2, . . . , (C2-1); and generating the reference data according to the seed data.