privacyIDEA is a modular solution for two factor authentication especially with OTP tokens. Due to the modular structure it can be quickly and easily adapted and enhanced. E.g. adding new token types is as simple as writing a new lean python module. You do not need to modify your network for privacyIDEA, it does not write to existing databases or user stores. It only needs read access to your user stores like LDAP, Active Directory, SQL, SCIM-service or flat files. privacyIDEA supports all usual push-button-tokens, OTP cards and smartphone apps.