What will the key open? A box? A door? In any case, it is a sign either that your unconscious is offering you access to your true self or, more modestly, a solution to a problem, or that life is offering you an opportunity to fulfil yourself or to exercise some hitherto unused talent.
An old man with keys may symbolize a deep inner source of wisdom. Follow him, and all secrets - your ‘destiny’/your real self - will be revealed.
The skeleton key is symbolic of potential, freedom and personal accessibility to previously unreachable goals. In all cases, the dream key illustrates a hopeful future and a real position to gain the benefits offered by an unknown future. In this sense, the key echoes a new-found faith and a sudden discovery of personal confidence. Accordingly, we need to interpret where we find the key, which specific locks can be opened, and which thresholds are subsequently crossed. However, if our key fails to open any locks whatsoever, our Unconscious may be revealing false hope witnessed in a (transient) waking situation.
Obviously the symbolism of the key relates to its twofold function of ‘unlocking’ and ‘locking’. It plays the double part of letting in and shutting out, a role underlined by the attribution of the keys of the Kingdom of Heaven to St Peter. The power of the keys is that of binding or loosing and of opening or shutting Heaven, a power effectively granted by Christ to St Peter. (In alchemical terms this power is that of ‘coagulation’ and ‘dissolution’.) This power is emblazoned in the papal coat of arms by the two keys, one of silver and one of gold, which had previously been emblems of the Roman god, Janus. These dual aspects of power, one light and the other dark, correspond to spiritual authority and the duties of kingship, of which the respective aims, according to Dante, are admission to the Heavenly and to the Earthly Paradise or, in Hermetic terms, to the Greater and Lesser Mysteries. Janus’ keys also opened the gates of the solstices granting admission to the waxing or waning phases of the cycle of the year or to the respective realms of ying and yang which come into equilibrium at the equinoxes.
In Japan, keys are, generally speaking, a symbol of prosperity because they open the rice-store. But it is patently clear that the rice-store can contain spiritual food and that, in this context, the key with which one gains entry has the same significance as those already discussed.
In legends and folktales, the keys mentioned are very often three in number and they allow their owners access to three successive enclosures, or secret rooms, which are as many approaches to the mystery. Be they silver, gold or diamond, they mark separate stages in purification or initiation. In this context, the key symbolizes a mystery to be unravelled, a riddle to be solved or a difficult task to be done; milestones, in short, on the road of enlightenment and revelation.