Secrecy (noun)

1. The state of being hidden or kept secret.
2. The practice of keeping something secret.

Origin:

Late middle english (in the sense "the state of being secret"): from old french secrecie, from latin secretus "separate, retired, secret", past participle of secernere "set apart".

Examples:

1. The secrecy surrounding the project has been intense.
2. He kept the secrecy of the matter.
3. The secrecy of their relationship was kept for years.
4. He kept their discussions under secrecy.
5. She was sworn to secrecy about the matter.