In his chess game against Neal, Keller employs the opening known as the Center Counter Defense (also called the Scandinavian Defense). This is one of the oldest recorded openings in chess history, dating back to the year 1475. In chess notation, the opening variation as played is (1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5).
The dates of birth shown in Lang's and Keller's fake passports are the two characters' actors' real dates of birth.
At the prison, when Keller tells Neal he owes the Russians $2.5 million. Keller mentions an item worth that amount that Neal stole in Scotland 6 years prior. The actor who plays Keller, Ross McCall, is from Scotland.
When Lang is looking at his and Keller's fake passports, Keller's says his name is 'Andrew Lincoln' which is, coincidentally, the same name as British actor and Walking Dead star, Andrew Lincoln.