Keys, and the locks or padlocks they fit, are fascinating symbols, and have often been featured in many different genres of tattoo designs. Since the earliest times, great steps have been taken to secure personal property, be it material, familial, or spiritual. To protect a treasure chest filled with gold or a heart just as pure, humans have found ways to keep looters at bay. Locks and keys speak of the value of what is locked away, and imply 'restricted access'. Neither was heaven accessible without the prescribed 'keys to the kingdom', of which Christ made Peter the guardian.
It has been said by some modern inventors of keys that the most exquisite workmanship in lock-making was during the medieval era. Lock plates and key heads appeared with elaborate gothic mouldings and embellishment, and the precision mechanisms were close to perfection. Still, even the best and most beautiful were not so fool-proof that a good thief couldn't pick it. During the reign of England's Elizabeth I, the locksmith had become a valued trade, and more efficient and secure mechanisms began to appear.
A tattoo design featuring keys and locks may well symbolize an item that is, "one of a kind" to its wearer.
See also: Love Tattoo Index
