In certificate chain validation, a parent certificate is used to validate a child certificate. The child certificate can indicate which parent certificate can be used to validate it. In some situations, a child certificate may not contain a certificate authority identifier that can be used to identify the parent certificate. Instead, the child certificate can contain a hash value of a modulus of the parent public key that can be used to identify the parent certificate. The hash value of the modulus of the parent public key can be associated with the parent public key. As such, the parent public key used in certificate chain validation of the child certificate can be identified using the hash value of the modulus of the parent public key.