Introducing Shared Memos

Coin Ninja ⚡
Mar 4, 2019 · 3 min read

Safe, encrypted and useful for everyday transactions

In In continuing with the mission to make using and sending Bitcoin more user friendly, the DropBit app has released its feature to Securely Send Memos. This is a unique to our wallet feature that significantly enhances the user experience for those users who send or receive multiple Bitcoin transactions in their wallet.

Many wallets offer the ability to add local memos to a wallet transaction, but no other wallet solution offers the capability to securely share memos between sender and recipient. The DropBit user has the ability to decide at each transaction if they want to share the memo with the recipient or if they just want to keep the memo private, on their own wallet. Not only does DropBit allow this powerful capability, it does so while keeping the messages encrypted and secure.

The shared memo feature works for both Android and iOS, allowing users to decide with each transaction if they want to add a memo and keep it to themselves, or securely share the memo with the recipient. This brings Bitcoin closer to the standard and ease of use of some FIAT wallets, like Cash App and Venmo, in which the memo is an important part of the transaction experience. Gone are the days where recipients and senders are left guessing which transaction was sent or received for which reason when looking at their transaction history.

For power users, or even merchants, this becomes even more important as memos give an ability to catalog activity between the user and recipient. In the comparison graphic below, you can see the image on the right is much more helpful when looking at transaction history.

Left: Transactions listed from BRD Wallet. Right: Transactions with Secure Shared Memos from DropBit

Transactions with Securely Shared Memos

Some other wallets allow you to add a memo to a transaction, but it only shows up on the memo creator’s wallet. DropBit allows for this capability as well, but there is a lot of power in being able to share this memo with the Bitcoin recipient.

As important to us as enhancing the utility and user experience of Bitcoin transactions are to us, ensuring that privacy remains unaffected by the features we implement is most important.

Shared memos are encrypted by using the Elliptic-curve Diffie-Hellman Ephemeral (ECDHE) key agreement protocol and AES-256-CBC. ECDHE requires two keys in order to work: our API stores a receiver’s address and corresponding public key, the sender generates an ephemeral key pair. The ECDHE shared secret is used to encrypt the memo which is then temporarily stored by our API. When the receiver sees a new transaction for that address it checks for any memos and the process is performed in reverse using the ephemeral public key and the corresponding private key for that address.

International Accessibility + Open Source Transparency coming soon…

In the coming weeks, DropBit will be made available in almost every country globally. We have heard from countless people who want to use DropBit around the world and soon that restriction is lifted. Additionally, we’ll be working on localizing languages and native currency to a handful of countries in the coming months.

Finally, we have also heard the requests for open source and we are in the final testing phase to open source the DropBit Wallet. Verification is essential in the Bitcoin space, and we are happy to open our solution up to the world so they can have the confidence to make DropBit one of their primary Bitcoin wallet solutions.

Coin Ninja

Accelerating the global adoption of Bitcoin

Coin Ninja ⚡

Written by

Accelerating the global adoption of Bitcoin. Check out the DropBit mobile Bitcoin wallet at

Coin Ninja

Accelerating the global adoption of Bitcoin

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