WhatsApp has become one of the most popular messaging apps, with over 2 billion users worldwide. One of the key features of WhatsApp is voice and video calling. But how secure are WhatsApp calls compared to regular phone calls? Here we examine the encryption and security features of WhatsApp calls versus normal calls.
Encryption of WhatsApp Calls
All WhatsApp calls, both voice and video, are end-to-end encrypted. This means the communication is encrypted on the sender’s device and only decrypted on the recipient’s device. Specifically, WhatsApp uses the Signal protocol for encrypting all calls.
The Signal protocol uses advanced end-to-end encryption methods like the AEAD encryption algorithm. It generates new keys for each call to prevent any calls from being decrypted if one set of keys is compromised. The keys are exchanged between devices using the Triple Diffie-Hellman key exchange algorithm to prevent man-in-the-middle attacks.
WhatsApp servers do not have access to the encryption keys used during calls. The company cannot decrypt or listen into WhatsApp calls. Only the communicating devices have the keys to encrypt and decrypt the call data.
Limitations of WhatsApp Call Encryption
While WhatsApp call encryption is very secure, there are some limitations:
- The encryption keys are based on the unique Signal Protocol key pair associated with each device. If an attacker compromises a device and extracts these keys, they could decrypt calls.
- Group calls involving more than two participants are not end-to-end encrypted. The encryption is from each participant to WhatsApp’s servers.
- The encryption does not prevent metadata, such as who is calling whom and when calls occurred, from being collected by WhatsApp.
Encryption of Normal Phone Calls
Normal phone calls made over a cellular network or landline are typically not encrypted. The voice data is transmitted openly over the network and can be intercepted by the phone carrier or any party tapping the communication lines.
Some key differences in security compared to WhatsApp calls:
- No end-to-end encryption between devices. The carrier has access to call data.
- Easily intercepted over the open cellular or phone network.
- Metadata like caller ID and call timing is openly available.
Landline and cellular calls do have some physical security advantages. It requires physical access to tap the phone lines to intercept a call. WhatsApp calls can be intercepted remotely if device keys are extracted.
Efforts to Encrypt Normal Calls
There are some technologies that try to add encryption to regular phone calls:
- ZRTP – A protocol that enables end-to-end encryption for VoIP calls by generating per-call symmetric keys.
- SRTP – Extends RTP audio protocol to enable encryption, message authentication and integrity.
- VoLTE – Encrypts 4G LTE data and voice packets between the device and cellular tower.
However, these are not commonly deployed on most networks. The infrastructure and device support required is often lacking.
Network Security
WhatsApp calls exchange all call data over the internet via WhatsApp’s servers. Normal calls rely on traditional cellular networks or landline networks.
Both WhatsApp and cellular networks employ security measures like firewalls, intrusion detection, rate limiting etc. to prevent attacks and abuse. However, internet networks are exposed to more security threats than traditional phone networks.
Internet calls must also contend with risks like:
- Malicious hotspots capturing traffic
- Insecure public WiFi networks
- Potential vulnerabilities in VoIP protocols
Cellular networks have dedicated infrastructure and years of security improvements to their advantage. But no network is completely immune to cyber attacks.
Metadata Protection
While WhatsApp calls are encrypted, the metadata can still be collected by WhatsApp. This includes details like who called whom, when the call occurred, call duration etc.
WhatsApp may use metadata internally for purposes like troubleshooting or analytics. They claim to not share any call metadata with third parties. But it is not possible for users to independently verify this.
Normal phone calls also have all metadata exposed to the phone carrier at a minimum. Telecom providers routinely share metadata with government agencies as well. There is no practical way for users to hide metadata for traditional calls.
Which Is More Secure?
In summary, here are the key comparative security advantages of WhatsApp calls over normal voice calls:
| Security Criteria | WhatsApp Call | Normal Voice Call |
|---|---|---|
| End-to-end encrypted | Yes | No |
| Open to carrier interception | No | Yes |
| Exposed to remote interception | Yes | No |
| Metadata protection | No | No |
Based on this comparison, WhatsApp calls are clearly more secure than regular voice calls in most situations. The end-to-end encryption implemented by WhatsApp provides a significant security advantage.
However, WhatsApp calls also rely on the internet which exposes them to some interception risks. Normal calls do not have this remote attack exposure. But their lack of encryption makes regular calling risky overall.
Conclusion
In conclusion, WhatsApp calls provide significantly better security than normal voice calls thanks to their end-to-end encryption implementation. While there are some limitations, WhatsApp calls eliminate the biggest security threat – interception of call content by third parties.
For users that want to keep their call data private, WhatsApp is currently the most secure and convenient option. The encryption protocols used are state-of-the-art and prevent even WhatsApp itself from accessing call data.
However, users should be aware that call metadata remains visible to WhatsApp. There are also infrastructure risks of calls traveling over the internet. Proper precautions should be taken, like avoiding public WiFi for sensitive calls.
Overall, WhatsApp calls are a major step up in voice call privacy over unsecured traditional calling. As more communications move onto internet platforms, adopting end-to-end encryption will only become more critical for protecting user privacy.