As per specifications document,

"We have the natural restriction that at least two characters must be ciphered, i.e. $b \geq 2$"

where each character is represented by an integer of certain cardinality. So basically a $2$ integer array is the minimum.

However say I want to encrypt a single input integer derived from the rank then encipher method - say I have a year between 1001 and 3000. Using the rank then encipher method, I would rank all the years I want to encrypt first to the values {0,1,2,...1999} and then encipher that value using an integer FPE.

EDIT: Can BPS work as an integer FPE as described in the paper titled 'Format Preserving Encryption' by Bellare and Rogaway? If so how?

As per specifications document,

"We have the natural restriction that at least two characters must be ciphered, i.e. $b \geq 2$"

where each character is represented by an integer of certain cardinality. So basically a $2$ integer array is the minimum.

However say I want to encrypt a single input integer but restrict it to a certain range. For example say the cardinality of the integer was $2000$ (so the range of possible values from $0 - 1999$).

Can this be done using BPS? (i.e. Would it be acceptable to simply input an integer array of size one to the algorithm with the cardinality as the range I want?)

I am trying to encrypt a year, but in a way that does not result in a year greater than current year.

As per specifications document,

"We have the natural restriction that at least two characters must be ciphered, i.e. $b \geq 2$"

where each character is represented by an integer of certain cardinality. So basically a $2$ integer array is the minimum.

However say I want to encrypt a single input integer but restrict it to a certain range - say a year between 1001 and 3000. Using the rank then encipher method, I would rank all the years I want to encrypt first to the values {0,1,2,...1999} and then encipher that value instead using an integer FPE.

EDIT: Can BPS work as an integer FPE as described in the paper titled 'Format Preserving Encryption' by Bellare and Rogaway? If so how?

As per specifications document,

"We have the natural restriction that at least two characters must be ciphered, i.e. $b \geq 2$"

where each character is represented by an integer of certain cardinality. So basically a $2$ integer array is the minimum.

However say I want to encrypt a single input integer derived from the rank then encipher method - say I have a year between 1001 and 3000. Using the rank then encipher method, I would rank all the years I want to encrypt first to the values {0,1,2,...1999} and then encipher that value using an integer FPE.

EDIT: Can BPS work as an integer FPE as described in the paper titled 'Format Preserving Encryption' by Bellare and Rogaway? If so how?