Random seed
From Tardis Wiki, the free Doctor Who reference
A random seed was used by a Randomiser to calculate algorithmic impossibilities.
When the Time Lords caught up with Compassion after learning the original code, the Eighth Doctor attempted to evade them again by using 8.23 as his new seed code based on a bad experience his companion Fitz Kreiner had with wasps as a child - he was stung twenty-three times after finding a nest when he was eight - reasoning that it was a number the Time Lords couldn't predict based on their knowledge of him and noting that the seed code simply had to be random rather than complex. (PROSE: The Ancestor Cell)
