Indian courts are examining whether police can compel a suspect to unlock their smartphone, pitting Article 20(3)'s right against self-incrimination against investigative necessity. The debate intensified after the Bharatiya Nagarik Suraksha Sanhita 2023 replaced the CrPC, retaining provisions on search and seizure without resolving the digital privacy gap. The Supreme Court's Puttaswamy ruling (2017) established privacy as a fundamental right under Article 21, creating a direct constitutional conflict when law enforcement demands biometric or passcode phone access.

Article 20(3) states that no person accused of an offence shall be compelled to be a witness against himself. The classic interpretation covered oral testimony and documents voluntarily prepared. The Supreme Court in State of Bombay v. Kathi Kalu Oghad (1961) drew a crucial distinction: providing a physical specimen (blood sample, fingerprint, handwriting) is NOT testimonial compulsion, but compelling someone to produce incriminating information from their mind IS protected.

Smartphone unlocking sits at the intersection of both categories. A biometric unlock (fingerprint, face ID) resembles a physical specimen — courts have generally held it is not protected by 20(3). A passcode or PIN, however, is purely testimonial — it reveals the contents of the accused's mind — and is strongly protected.

The Supreme Court's K.S. Puttaswamy v. Union of India (2017) added a second layer: even where 20(3) does not protect, Article 21's right to privacy requires that any intrusion satisfy the three-pronged test of legality (law authorising it), legitimate aim, and proportionality.

The BNSS 2023 under Section 185 allows search of electronic devices during investigation, but does not expressly authorise compelling decryption. Courts increasingly hold that a direction to decrypt must pass both the Kathi Kalu Oghad testimonial test and the Puttaswamy proportionality test before it can be enforced.