Juinjutsu (呪印術, Literally meaning: Cursed Seal Techniques) are a type of techniques used to bring someone under the control of the user. By applying a seal to the victim's body, the user brings the victim's abilities and actions under his/her control. With a simple secret hand seal, the user can inflict great mental and physical torment on the victim. The exact workings of juinjutsu are kept secret.
Juinjutsu was believed to be originated within Jugo then extracted from him and used by Orochimaru