点按 新增标签，建立新的标签名称与新增成员，或于新增成员中，将朋友加入已设定的标签内。
The servers keep registered customers' phone quantities, public vital materials and force tokens which happen to be essential for organising calls and transmitting messages.[174] To be able to determine which contacts are Sign consumers, cryptographic hashes from the person's Get hold of figures are periodically transmitted to the server.[a hundred seventy five] The server then checks to view if These match any of your SHA-256 hashes of registered end users and tells the consumer if any matches are uncovered.[one hundred seventy five] The hashed numbers are thereafter discarded with the server.[174] In 2014, Moxie Marlinspike wrote that it is straightforward to compute a map of all possible hash inputs to hash outputs and reverse the mapping as a result of restricted preimage Place (the set of all doable hash inputs) of cellphone quantities, and that a "realistic privacy preserving Speak to discovery remains an unsolved dilemma.
[152][153] In July 2017, scientists from RUB found in the course of One more Assessment of team messengers a purely theoretic assault against the group protocol of Signal: A user who is aware The key team ID of a bunch (as a consequence of having been a group member previously or stealing it from a member's device) can become a member from the group. Because the group ID cannot be guessed and this kind of member adjustments are displayed to the remaining associates, this attack is likely to be difficult to carry out without being detected.[154]
TextSecure authorized the consumer to set a passphrase that encrypted the neighborhood message database and also the user's encryption keys.[127] This didn't encrypt the consumer's Speak to database or message timestamps.[127] The Sign apps on Android and iOS might be locked With all the telephone's pin, passphrase, or biometric authentication.
Sign's app icon might be adjusted with many different colour themes for personalisation and to hide the application. The application title may also be custom made.[132] Messages can have outcomes like spoilers and italics, and customers can insert one another by way of QR code.[133]
On nine August 2022, Ismail Sabri Yaakob, the Prime Minister of Malaysia, documented that his Sign account was "hacked" and infiltrated by a third party, sending out messages and impersonating the politician. No information were being disclosed regarding the strategy utilized to check here obtain use of the account.[215]
On 4 October 2016, the American Civil Liberties Union (ACLU) and Open Whisper Systems published a number of files revealing that OWS experienced acquired a subpoena necessitating them to provide info related to two phone quantities for your federal grand jury investigation in the 1st 50 percent of 2016.[82][83][eighty four] Only among the list of two mobile phone numbers was registered on Sign, and since of how the provider is created, OWS was only able to supply "the time the person's account were developed and the last time it experienced connected to the service".
Sign needs which the consumer supply a phone variety for verification,[141] removing the need for consumer names or passwords and facilitating Make contact with discovery (see below).[142] The range does not have to be similar to around the machine's SIM card; it can be a VoIP quantity[141] or simply a landline assuming that the user can obtain the verification code and have a different unit to create the software package.
Until eventually 2023, Android consumers could choose into building Signal the default SMS/MMS software, allowing for them to deliver and obtain unencrypted SMS messages In combination with the common finish-to-close encrypted Signal messages.
创建安全群组，与朋友、家人和同事保持联系，同时享有所有隐私功能�?高级隐私功能
Among the things which I used to be briefed on extremely early, senator, was because of the CIA information administration people about the use of Signal as a permissible get the job done use," Ratcliffe stated. ^
The group messaging mechanism is intended so which the servers do not have use of the membership record, group title, or group icon.
The assert that Sign is accustomed to fund terrorist or legal pursuits may be the justification for Turkey to criminalize the app for the overall population, which Abdullah Bozkurt statements is a method the "authorities abuses its counterterrorism guidelines to punish critics, opponents and dissidents."[243][244]
Signal utilizes mobile phone quantities to register and deal with person accounts, even though configurable usernames ended up added in March 2024 to allow people to cover their cellphone figures from other buyers.