Diffie-Hellman Picture Show: Key Exchange Stories from Commercial VoWiFi Deployments
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916349276585984 |
|---|---|
| author | Gegenhuber, Gabriel Karl Holzbauer, Florian Frenzel, Philipp Weippl, Edgar Dabrowski, Adrian |
| author_facet | Gegenhuber, Gabriel Karl Holzbauer, Florian Frenzel, Philipp Weippl, Edgar Dabrowski, Adrian |
| contents | Voice over Wi-Fi (VoWiFi) uses a series of IPsec tunnels to deliver IP-based telephony from the subscriber's phone (User Equipment, UE) into the Mobile Network Operator's (MNO) core network via an Internet-facing endpoint, the Evolved Packet Data Gateway (ePDG). IPsec tunnels are set up in phases. The first phase negotiates the cryptographic algorithm and parameters and performs a key exchange via the Internet Key Exchange protocol, while the second phase (protected by the above-established encryption) performs the authentication. An insecure key exchange would jeopardize the later stages and the data's security and confidentiality.
In this paper, we analyze the phase 1 settings and implementations as they are found in phones as well as in commercially deployed networks worldwide. On the UE side, we identified a recent 5G baseband chipset from a major manufacturer that allows for fallback to weak, unannounced modes and verified it experimentally. On the MNO side -- among others -- we identified 13 operators (totaling an estimated 140 million subscribers) on three continents that all use the same globally static set of ten private keys, serving them at random. Those not-so-private keys allow the decryption of the shared keys of every VoWiFi user of all those operators. All these operators deployed their core network from one common manufacturer. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2407_19556 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Diffie-Hellman Picture Show: Key Exchange Stories from Commercial VoWiFi Deployments Gegenhuber, Gabriel Karl Holzbauer, Florian Frenzel, Philipp Weippl, Edgar Dabrowski, Adrian Cryptography and Security Networking and Internet Architecture Voice over Wi-Fi (VoWiFi) uses a series of IPsec tunnels to deliver IP-based telephony from the subscriber's phone (User Equipment, UE) into the Mobile Network Operator's (MNO) core network via an Internet-facing endpoint, the Evolved Packet Data Gateway (ePDG). IPsec tunnels are set up in phases. The first phase negotiates the cryptographic algorithm and parameters and performs a key exchange via the Internet Key Exchange protocol, while the second phase (protected by the above-established encryption) performs the authentication. An insecure key exchange would jeopardize the later stages and the data's security and confidentiality. In this paper, we analyze the phase 1 settings and implementations as they are found in phones as well as in commercially deployed networks worldwide. On the UE side, we identified a recent 5G baseband chipset from a major manufacturer that allows for fallback to weak, unannounced modes and verified it experimentally. On the MNO side -- among others -- we identified 13 operators (totaling an estimated 140 million subscribers) on three continents that all use the same globally static set of ten private keys, serving them at random. Those not-so-private keys allow the decryption of the shared keys of every VoWiFi user of all those operators. All these operators deployed their core network from one common manufacturer. |
| title | Diffie-Hellman Picture Show: Key Exchange Stories from Commercial VoWiFi Deployments |
| topic | Cryptography and Security Networking and Internet Architecture |
| url | https://arxiv.org/abs/2407.19556 |