Blowfish was an algorithm used to encrypt data.
Day 4 Edit
Between 1:00 AM and 2:00 AM, Chloe O'Brian discovered files on Sabir Ardakani's computer that were encrypted using the Blowfish algorithm. Chloe claimed the files could be decrypted using a proprietary CTU algorithm.
Day 5 Edit
Chloe made reference to a data file being encrypted using a Triple Blowfish variant.
Day 7 Edit
Morris O'Brian decrypted files to find out the location of Jack's target.