Mudamos: Electronic Signatures

Sign bills of popular initiative by using your mobile phone


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The Mudamos app, which collects electronic signatures for citizens’ initiative laws was developed to transform the way laws are proposed by the public. Citizens’ initiative until this day is based on paper forms, but this collection method, besides being costly, has serious issues regarding transparency of the process.

In practice, no bill created through citizen’s initiative till this moment has verified its signatures due to this being a technical impossibility. All citizen’s initiative bills had to be “adopted” by a member of congress to then be presented.

ITS Rio believes technology can change the way this data is collected and thus, developed a smartphone app to demonstrate how it is possible to sign electronically citizens’ initiative laws. We used the same technology as information security companies, in which each user signature is verified by a pair of public and private keys – this guarantees the authenticity and uniqueness of each signature.

The whole process is made using public algorithms, available as open source in our code repository ( and can be used by any person or entity that wishes to verify signatures. To guarantee isonomy for ITS during collection of signatures, all signature lists are registered in a blockchain, which authenticates the list daily and guarantees protection against fraud. Not even ITS Rio, or any other person has the power to manipulate these lists once they’re registered.

The app was developed with resources from the Google Impact Challenge award and was launched in April 2017. It can be used not only to propose new legislation at a federal level (which requires 1,5 million signatures), but also at state and municipal levels. In these cases, the number of signatures is far lower: It can be 60 thousand signatures for states and just 300 for most municipalities in Brazil.

We believe municipal lawmaking can be entirely transformed with use of the Mudamos+ (We Change+) app and will create a new relationship between representatives and the represented.

ITS Rio has held meetings with several Brazilian legislative bodies, such as the National Congress, as well as state legislative assemblies and city councils to regulate this electronic form of signatures.

ITS Rio reinforces its public commitment of offering creative solutions for social challenges. Thus, ITS is available for counsel to these legislative bodies with technical, judicial, and legislative support to regulate the electronic registration of voters. This is done by ITS sharing its technology and templates for legislative acts to create a new scenario for citizens’ initiative in Brazil.