UIDAI is mandated to issue an easily verifiable 12 digit random number as Unique Identity - Aadhaar to all Residents of India. UIDAI is mandated to issue an easily verifiable 12 digit random number as Unique Identity - Aadhaar to all Residents of India. India's UIDAI has introduced a new Aadhaar app for smartphones. This free app allows citizens to securely carry their digital Aadhaar card, eliminating the need for physical copies. Features ... UIDAI is mandated to issue an easily verifiable 12 digit random number as Unique Identity - Aadhaar to all Residents of India.