whats wrong with Instagram ?

they own your images

(if they go offline, your images do)

all or nothing access control

their image urls are public

Approach

• Keep your profile on your own machine!
• Encrypt the images before storing them!
• Provide access to every follower individually!

obvious disclaimer: you always can

make a screenshot

some facts about instagram

• a Facebook company
• owns 40bn photos
• 800 million monthly active users
• business model: analyse your photos to present ads
• (they may use your pictures for anything)
• they can be hacked (2017!), sold, ddosed at any time

Blockstagram

decentralized instagram

Safely Persisting images

• blockstack.id: source for trusted user profiles
• use a distributed file storage
  • use blockstack's gaia hub
  • or bring your own trusted storage
• look ma, no public image urls
  • (getFile API)
• symmetrically encrypt image data

store images

dyrk.id

image/<md5>

image/<md5>

image/<md5>

storage

custom symmetric
aes certificate

There is no "image server"

it even looks like instagram

Share your images

dyrk.id

custom symmetric
aes certificate

"password"

Others cannot read your images

dyrk.id

stadolf.id

1. encrypt your secret 

dyrk.id

stadolf.id

public
key

dyrk encrypts his secret aes key
("password") with stadolf's public key

"please add me"

ok

2. share the secret 

dyrk.id

stadolf.id

public
key

private

stadolf decrypts dyrk's key with his private key.
He now has dyrk's key to the file

stored
@stadolf

3. grant access

dyrk.id

stadolf.id

public

4. revoke access (Poc)

1. create a new AES key
2. reencrypt all the images' hashed locations
3. your followers' old "password" stops working 
4. every follower repeats the grant step
5. followers you don't want don't get the new password

Is dyrk happy now?

• safe, encrypted storage of his images
• simple & private access management
• it looks like Instagram (meh)

I think he's happy now :)

(c) Facebook

Is the team happy now?

(c) Instagram

https://twitter.com/PatrickWStanley/status/970307376690626561

https://github.com/coding-berlin/blockstagram

(c) Twitter

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