Electronic passports contain an embedded microchip that stores and processes data securely. The chip adheres to ICAO standards, such as Doc 9303, and is typically based on contactless smart card technology. It incorporates cryptographic modules and memory for storing various passport-related information.

ePassports employ various security mechanisms to protect the integrity and confidentiality of the stored data. Cryptographic algorithms, such as RSA or Elliptic Curve Cryptography (ECC), are used for secure communication and data encryption. Secure messaging protocols, such as the Basic and Supplemental Access Control (BAC and SAC), ensure the confidentiality of data during transmission.

ePassports prioritize privacy protection by implementing secure authentication mechanisms and data encryption. The biometric and personal information stored within the chip is securely stored and cannot be easily accessed or tampered with. Additionally, the chip only releases the necessary data to authorized entities during the authentication process, minimizing the exposure of sensitive information.

The ePassport ICAO application includes biometric data of the passport holder, which is captured and stored in a digital format within the microchip. This biometric data typically includes facial images and may also include fingerprints or iris scans, depending on the specific implementation. The biometric data enables automated identity verification at border control points.

The ePassport chip supports digital signatures to ensure the authenticity and integrity of passport data. Digital signatures are applied to the biometric and non-biometric data stored in the chip, using the passport issuing authority's private key. This enables verification of the passport's authenticity during the authentication process.

PIV cards rely on a hierarchical certificate authority (CA) infrastructure. The government operates a root CA that issues certificates to intermediate CAs, which, in turn, issue certificates to individual PIV cards. This hierarchical structure ensures the integrity and authenticity of the certificates used in the PIV ecosystem.

The ePassport chip follows specific data structures defined by ICAO. These structures include the Basic Access Control (BAC) mechanism, which provides a secure channel for accessing passport data, and the Extended Access Control (EAC) mechanism, which enhances security by using stronger cryptographic algorithms for authentication and data protection.​

ePassports still include a machine-readable zone at the bottom of the passport's data page. The MRZ contains key passport information, such as the holder's name, date of birth, and passport number, in a standardized format. This allows compatibility with existing passport readers while providing a fallback mechanism in case the electronic components of the passport are unavailable or damaged.