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.