Aren't these cards using NFC also running Java, just like most (all?) smartcards?

NFC doesn't preclude TLS:

> I'm currently analyzing the possibilities of using Yubikeys for TLS client certificate authentication over NFC on iOS devices as part of a single sign-on process, but from what I have been able to gather only OTP seems to been supported? Are there any plans for supporting PIV over NFC?

* https://github.com/Yubico/yubikit-ios/issues/5 (functionality added)

> This paper introduces a new online payment protocol called EMV-TLS, dealing with NFC enabled mobiles. EMV-TLS results from the merging of three technologies: EMV payment applications, SSL/TLS secure channels, and Near Field Communication radio interfaces. The main idea of this protocol is to remotely use an EMV-TLS chip, thanks to a secure TLS channel established with a server. The mobile acts as a passive modem that manages TCP/IP resources. Two classes of servers are defined; N1 class may only read the embedded information (card number, bearer name, validity date,), while N2 class has access to all chip resources and may generate cryptograms. A first experimental platform including an EMV-TLS chip, an Android mobile, and a TLS payment server has been realized as an early proof of concept.

* https://ieeexplore.ieee.org/document/6867565

> This paper introduces a new mobile service, delivering keys for hotel rooms equipped with RFID locks. It works with Android smartphones offering NFC facilities. Keys are made with dual interface contactless smartcards equipped with SSL/TLS stacks and compatible with legacy locks. Keys cards securely download keys value from dedicated WEB server, thanks to Internet and NFC connectivity offered by the Android system. We plan to deploy an experimental platform with industrial partners within the next months.

* https://eudl.eu/pdf/10.1007/978-3-642-32320-1_30

    This document describes the support of the TLS protocol over the NFC
    (Near Field Communication) LLCP (Logical Link Control Protocol)
    layer, which is referred as LLCPS. The NFC peer to peer (P2P)
    protocol may be used by any application that needs communication
    between two devices at very small distances (a few centimeters).
    LLCPS enforces a strong security in NFC P2P exchanges, and may be
    deployed for many services, in the Internet of Things (IoT)
    ecosystem, such as payments, access control or ticketing operations.
    Applications secured by LLCPS are identified by the service name
    "urn:nfc:sn:tls:service".

* https://datatracker.ietf.org/doc/html/draft-urien-tls-llcp

It's definitely possible: eSIM provisioning uses TLS too, as far as I know (between the eSIM chip and the provisioning service).

Not at all: NFC (or more accurately ISO 14443) is often used as just another interface for regular ISO 7816 smartcards.

There are other contactless standards (storage only, proprietary fixed-function logic etc.) too, but full-fledged Java Card smartcards are actually quite common: It’s what most contactless payment cards are.

Interesting thank you.

I always thought only a subset of the capabilities of Java Cards were available in NFC mode due to power restriction reasons.