Text messaging is one of the most common ways people communicate. Businesses use SMS to send important updates, while individuals rely on it for everyday conversations. But have you ever thought, “Is texting secure?” The answer is not really.
While other modern messaging app services employ advanced encrypted message protection, SMS encryption does not exist in mobile phone networks. This makes your SMS inbox highly vulnerable to hackers, network breaches, and interception. If you’re concerned about privacy, it’s essential to understand how SMS encryption works and how you can secure your messages.
In this blog, we’ll explain SMS encryption, whether SMS is secure, the risks of unencrypted messages, and how you can protect your text conversations.
What is End-to-End Encryption?
Encryption is a security operation that scrambles data so that only the authenticated parties can read it. End-to-end encryption primarily uses asymmetric cryptography, which means that a unique pair of public and private keys encrypts and decrypts messages.
Unlike symmetric encryption (used in SSL/TLS), this ensures only the recipient can decode the message, eliminating the need for a shared key that could be intercepted.
How Does E2EE Work?
- When you send a message, encryption is performed on your device before transmission.
- The message travels through the network in encrypted form, and no one can read it except the person who is important in the transmission.
- The message can only be decrypted and read by the device user.
Example: When you send a message on WhatsApp or Signal, even the companies running these platforms cannot read it because the encryption keys exist only on your device and the recipient's device.
Is SMS Encrypted?
The main concern about SMS security is that standard text messages are not encrypted.
This means:
- Messages go unencrypted across cellular networks.
- Your mobile carrier may be able to read and store messages you send via SMS.
- Hackers can intercept SMS messages.
- Governments and law enforcement can get hold of your messages.
Unlike modern messaging, which prioritizes text message encryption, SMS is built on outdated technology that lacks built-in security measures. If you frequently use SMS for communication, it’s important to explore secure alternatives or features like schedule a text message to manage your messages more effectively while staying cautious about privacy risks.
Don’t Let Cyber Threats Compromise Your Security!
Leverage ControlHippo to safeguard sensitive information and enhance communication efficiency.
How SMS Messages Travel & Why They’re Not Secure
When you send an SMS, the trail of your message follows these steps:
- Your phone sends the message to your carrier’s network.
- The carrier passes the message to the recipient’s carrier.
- The recipient spots the message on the phone.
Messages may be intercepted, logged, or read at any point during this process. Hence, although extremely sensitive conversations must take place, security experts do not recommend using SMS.
According to the Open Web Application Security Project (OWASP), SMS messages are vulnerable at multiple points in transit. Attackers can exploit vulnerabilities in SS7 (Signaling System No. 7), the protocol carriers use to route messages, making interception possible.
Understanding the Risks of Not Encrypting SMS
As SMS is unencrypted, it may involve some risk in passing important messages. Here are some of the reasons SMS messaging is insecure:
1. Hackers Can Intercept SMS Messages
Cybercriminals can use tools like IMSI catchers (fake cell towers), technically called cell tower simulators, to intercept SMS messages. If you have been discussing financial data, business deals, or something personal over SMS, chances are that a hacker can read what you are talking about as it happens.
Real-world Example: Some hackers hacked into a cryptocurrency account by intercepting SMSs for passwords, costing millions in 2020.
2. SIM Swapping Attacks
SIM swapping is a serious attack today. A hacker persuades a mobile carrier to transfer a phone number to a new SIM card: once they control the number, they can:
- Read the victim’s text messages, one-time passcodes, and 2FA codes.
- Reset passwords for their bank, their email, and their social media logins.
- Impersonate the victim and scam their contacts.
Real-world Example: On February 11, 2025, an Alabama man admitted to hijacking the U.S. Securities and Exchange Commission (SEC) X account in a January 2024 SIM swap attack. This briefly sent Bitcoin soaring by $1,000, but it crashed by $2,000 when the SEC confirmed the post was fake.
3. SMS Phishing (Smishing) Scams
This type of scam involves fake SMS messages from fake banks, federal agencies, or widely known goods brands that cheat on their hapless victims, leading them to reveal their personal identifying information. A simple way, really, is SMS could have been taken for impersonating legitimate businesses as SMS takes no secure or verifiable path in being transmitted.
Example: You receive a fake text message supposedly from your bank asking you to click on a link to re-confirm your credentials.
According to a study, SMS phishing (smishing) scams led to over $330 million in reported losses, showing a 30% increase from the previous year. Cybersecurity experts at Norton recommend avoiding SMS-based verification for sensitive accounts.
Why Use SMS for Two-factor Authentication if It’s Not Encrypted?
The simple answer is convenience.
- SMS-based 2FA works on basically any phone, even old models.
- It is super easy for businesses to implement.
- It is better than doing it strictly by using passwords.
However, SMS-based 2FA is by no means the safest, as hackers can access verification codes through techniques such as SIM spoofing and SMS interception.
Alternatively, security experts strongly recommend moving away from SMS-based 2FA in favor of:
- Authenticator apps (Google Authenticate, Microsoft Authenticator, Authy)
- Hardware security keys (like YubiKey)
These methods eliminate the risks associated with SMS encryption vulnerabilities.
- Avoid sharing sensitive information over SMS.
- Use encrypted messaging apps like Signal or WhatsApp.
- Enable RCS encryption on Android Messages.
- Switch from SMS-based 2FA to an authenticator app.
How to Encrypt SMS Messages?
As regular SMS does not provide encryption, it is best to use alternative secure messaging solutions.
1. RCS
RCS is one of the newest upgrades of SMS that is endowed with improved messaging features and encryption of messages. It is equipped with read receipts, indicators on typing, and sharing of media content messages. One-to-one messaging is encrypted, but group chats do not enjoy this feature.
How to enable RCS encryption on Android?
- Open Google Messages.
- Go to Settings > Chat Features.
- Enable Chat Features (RCS).
How to enable RCS encryption on iOS?
For Apple users, RCS business messaging is now available, starting with iOS 18. However, you’ll need:
- A text-messaging plan from a carrier that supports RCS on iPhone.
- To enable RCS in settings, Go to Settings > Apps > Messages > RCS Messaging and turn it on.
: Short Welcome Messages, Quotes and Templates2. Third-Party Apps
The most secure alternative to SMS is end-to-end encrypted messaging apps such as:
- Signal is the most secure app without data tracking.
- WhatsApp uses E2EE but collects metadata.
- Telegram encryption is optional (only in Secret Chats).
These apps use fully encrypted text messages that hackers, surveillance, and breaches can’t touch.
Security experts widely recommend Signal due to its open-source encryption protocol and strict no-logs policy. WhatsApp, while encrypted, collects metadata such as message timestamps and contact information, which could pose privacy risks.
3. Android Messages
With Android Messages, one-on-one conversations can take place with encryption, provided both users have RCS activated.
How to Enable RCS Encryption?
- Open Google Messages.
- Go to Settings > Chat Features.
- Turn on Enable Chat Features.
It should be noted that groups and SMS to non-RCS users are not encrypted.
4. iMessage
Apple’s iMessage comes encrypted by default, but only when the sender and receiver both have iPhones. In iPhones:
- Blue bubbles=Encrypted (iMessage).
- Green bubbles=Unencrypted (SMS).
Conclusion
If you are still wondering which messaging method works best, SMS may stand out. However, the problem with SMS is that it isn’t encrypted. While this medium allows you to communicate quickly, it isn’t the ideal alternative for communicating sensitive information.
The hazards of unencrypted SMS highlight the need for more secure alternatives. If privacy and security matter, users must upgrade to encrypted messaging apps like Signal, WhatsApp, or iMessage. Android users can also switch to RCS for better security, although it has limitations.
Businesses should also reconsider using SMS for authentication and opt for safer alternatives, such as authenticator apps or security keys. As cyber threats evolve, it is important to make informed choices about communication security.
Updated : February 19, 2025
Priya Naha is a skilled technical content writer with a specialization in business communication and omnichannel communication platforms. Her expertise lies in translating complex concepts into clear, engaging content that resonates with diverse audiences. Focused on business communication solutions, Priya excels in delivering informative and practical insights through her writing.
Subscribe to our newsletter & never miss our latest news and promotions.
+21K people have already subscribed