A/HRC/29/32 have signed but not ratified the Covenant are bound to respect its object and purpose under article 18 of the Vienna Convention on the Law of Treaties. National legal systems also protect privacy, opinion and expression, sometimes with constitutional or basic law or interpretations thereof. Several global civil society projects have also provided compelling demonstrations of the law that should apply in the context of the digital age, such as the International Principles on the Application of Human Rights to Communications Surveillance and the Globalhttp://www.opensocietyfoundations.org/publications/globalprinciples-national-security-and-freedom-information-tshwane-principles Principles on National Security and the Right to Information. Although specific standards may vary from right to right, or instrument to instrument, a common thread in the law is that, because the rights to privacy and to freedom of expression are so foundational to human dignity and democratic governance, limitations must be narrowly drawn, established by law and applied strictly and only in exceptional circumstances. In a digital age, protecting such rights demands exceptional vigilance. A. Privacy as a gateway for freedom of opinion and expression 16. Encryption and anonymity provide individuals and groups with a zone of privacy online to hold opinions and exercise freedom of expression without arbitrary and unlawful interference or attacks. The previous mandate holder noted that the rights to “privacy and freedom of expression are interlinked” and found that encryption and anonymity are protected because of the critical role they can play in securing those rights (A/HRC/23/40 and Corr.1). Echoing article 12 of the Universal Declaration of Human Rights, article 17 of the International Covenant on Civil and Political Rights specifically protects the individual against “arbitrary or unlawful interference with his or her privacy, family, home or correspondence” and “unlawful attacks on his or her honour and reputation”, and provides that “everyone has the right to the protection of the law against such interference or attacks”. The General Assembly, the United Nations High Commissioner for Human Rights and special procedure mandate holders have recognized that privacy is a gateway to the enjoyment of other rights, particularly the freedom of opinion and expression (see General Assembly resolution 68/167, A/HRC/13/37 and Human Rights Council resolution 20/8). 17. Encryption and anonymity are especially useful for the development and sharing of opinions, which often occur through online correspondence such as e-mail, text messaging, and other online interactions. Encryption provides security so that individuals are able “to verify that their communications are received only by their intended recipients, without interference or alteration, and that the communications they receive are equally free from intrusion” (see A/HRC/23/40 and Corr.1, para. 23). Given the power of metadata analysis to specify “an individual’s behaviour, social relationships, private preferences and identity” (see A/HRC/27/37, para. 19), anonymity may play a critical role in securing correspondence. Besides correspondence, international and regional mechanisms have interpreted privacy to involve a range of other circumstances as well. 8 18. Individuals and civil society are subjected to interference and attack by State and non-State actors, against which encryption and anonymity may provide protection. In 8 Human Rights Committee, general comment No. 16 (1988) on the right to respect of privacy, family, home and correspondence, and protection of honour and reputation. See also European Court of Human Rights, factsheets on data protection (http://www.echr.coe.int/documents/fs_data_eng.pdf www.echr.coe.int/Documents/FS_Data_E NG.pdf) and right to protection of one’s image (http://www.echr.coe.int/documents/fs_own_image_eng.pdf www.echr.coe.int/Documents/FS_ Own_image_ENG.pdf). 7