What are the ongoing technical efforts to improve the security and privacy of phone number data on WhatsApp?

[muskanhossain]

When a phone number is recycled and assigned to a new user in Sirajganj, Rajshahi Division, Bangladesh, or anywhere else globally, WhatsApp employs several technical strategies to manage the transition and prevent the new user from accessing the previous owner's data. Here's a breakdown of the key aspects:

1. Monitoring Account Inactivity:
WhatsApp actively monitors accounts for inactivity. If an account oman whatsapp number data associated with a specific phone number remains unused for a significant period (reportedly around 45 days), the system recognizes this as a potential sign that the number might have been recycled by mobile carriers.

2. Removing Old Account Data:
If the inactivity threshold is met and the phone number is activated on a new mobile device with a fresh WhatsApp installation, WhatsApp automatically clears the old account data tied to that phone number. This includes the profile photo and "About" information. This step helps prevent the new user from seeing the previous owner's public profile details.

3. Verification Process for New Users:
When the new user registers WhatsApp with the recycled phone number on their device in Sirajganj, they undergo the standard verification process. This involves WhatsApp sending a one-time code (OTP) via SMS to the phone number. The new user must enter this code to confirm they currently control the phone number. This step is crucial to establish a new, secure association between the phone number and the new user's device.

4. Secure Linking to the New Device:
Upon successful verification, a new WhatsApp account and a new set of end-to-end encryption keys are generated and securely linked to the recycled phone number on the new user's device. The previous account and its associated encryption keys become inactive and inaccessible. WhatsApp accounts are tied to the specific device they are actively registered on. While the multi-device feature allows linking additional devices, only one phone can be the primary device associated with the phone number at any given time. Registering the number on a new primary device automatically logs out the account from the old primary device.

5. Notification to Contacts (Potential for Confusion):
A potential point of confusion arises because contacts of the new user in Sirajganj (or elsewhere) might still see the phone number associated with the previous owner's name in their phone's address book until they manually update it. WhatsApp displays the names saved in the user's local address book, not necessarily the current WhatsApp account holder's name. WhatsApp advises users to regularly manage their contacts and delete numbers of individuals they no longer communicate with to mitigate this.

6. Two-Step Verification as a Security Layer:
If the previous owner of the recycled phone number had enabled two-step verification with a PIN, the new user in Sirajganj might encounter a prompt to enter this PIN after successfully verifying their phone number. WhatsApp provides a mechanism to reset the PIN if the previous owner had added an email address to their account. If no email was associated, the new user may have to wait for seven days after the last successful online activity of the old account before they can reset the PIN and gain full access. This waiting period acts as a security measure to prevent unauthorized access.

7. No Access to Previous Chats:
Importantly, the new user in Sirajganj cannot access the previous owner's chat history or other personal data. WhatsApp's end-to-end encryption ensures that message content is encrypted on the sender's device and can only be decrypted on the intended recipient's device using unique cryptographic keys. When a new account is created on a new device (even with a recycled number), a new set of encryption keys is generated, rendering previous conversations inaccessible. WhatsApp does not typically store delivered messages on its servers.

In summary, WhatsApp handles recycled phone numbers by automatically clearing old profile data after inactivity and establishing a new, secure account linked to the new user's device upon successful verification. While contact name displays might persist based on local address books, the new user cannot access previous chats due to end-to-end encryption, and features like two-step verification provide an additional layer of security during the transition. WhatsApp also encourages users to manage their contact lists proactively.