Arcane Lock

(Player's Handbook v.3.5, page 200, DnD 3.5)

Abjuration

Level: ; Sorcerer/Wizard 2; Knight of the Weave 2; Thayan Slaver 1; Wu Jen 2; Sha'ir 2; Savant 2; Court Herald 2
Components: V, S, M
Casting Time: 1 standard action
Range: Touch
Target: The door, chest, or portal touched, up to 30 sq. ft./level in size
Duration: Permanent
Saving Throw: None
Spell Resistance: No

An arcane lock spell cast upon a door, chest, or portal magically locks it.
You can freely pass your own arcane lock without affecting it; otherwise, a door or object secured with this spell can be opened only by breaking in or with a successful dispel magic or knock spell.
Add 10 to the normal DC to break open a door or portal affected by this spell.
(A knock spell does not remove an arcane lock; it only suppresses the effect for 10 minutes).
Material Component: Gold dust worth 25 gp.