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Excel Secucard S300

🔍 Last analysed 23rd March 2022 . No source for current release found

Without public source of the reviewed release available, this product cannot be verified!

As part of our Methodology, we ask:

Is the source code publicly available?

If the answer is "no", we mark it as "No source for current release found".

A wallet that claims to not give the provider the means to steal the users’ funds might actually be lying. In the spirit of “Don’t trust - verify!” you don’t want to take the provider at his word, but trust that people hunting for fame and bug bounties could actually find flaws and back-doors in the wallet so the provider doesn’t dare to put these in.

Back-doors and flaws are frequently found in closed source products but some remain hidden for years. And even in open source security software there might be catastrophic flaws undiscovered for years.

An evil wallet provider would certainly prefer not to publish the code, as hiding it makes audits orders of magnitude harder.

For your security, you thus want the code to be available for review.

If the wallet provider doesn’t share up to date code, our analysis stops there as the wallet could steal your funds at any time, and there is no protection except the provider’s word.

“Up to date” strictly means that any instance of the product being updated without the source code being updated counts as closed source. This puts the burden on the provider to always first release the source code before releasing the product’s update. This paragraph is a clarification to our rules following a little poll.

We are not concerned about the license as long as it allows us to perform our analysis. For a security audit, it is not necessary that the provider allows others to use their code for a competing wallet. You should still prefer actual open source licenses as a competing wallet won’t use the code without giving it careful scrutiny.

The product cannot be independently verified. If the provider puts your funds at risk on purpose or by accident, you will probably not know about the issue before people start losing money. If the provider is more criminally inclined he might have collected all the backups of all the wallets, ready to be emptied at the press of a button. The product might have a formidable track record but out of distress or change in management turns out to be evil from some point on, with nobody outside ever knowing before it is too late.

Do your own research!

Try out searching for "lost bitcoins", "stole my money" or "scammers" together with the wallet's name, even if you think the wallet is generally trustworthy. For all the bigger wallets you will find accusations. Make sure you understand why they were made and if you are comfortable with the provider's reaction.

If you find something we should include, you can create an issue or edit this analysis yourself and create a merge request for your changes.

The Analysis 

Product Description

The Excel Secucard S300 Display card finds its origins as a secure authentication card for various purposes. It can be used as a secure means for identification prior to its usage as a cryptocurrency wallet. It has a 256x256 E-Ink display screen and 13-key keypad.

eSecuCard Display Card is the newest smart Java card on the market which supports big E-ink display screen. It can display images, QR codes and texts. Embedded with Secure Element and a Real-Time-Clock chip, the super smart card provides a great platform for users to develop various applets based on smart card usage scenarios, such as bitcoin wallet for cold storage and payment, membership card, password vault, employee card, electronic ticket card and etc.

One of Excel Secu’s other products, previously reviewed here has a striking resemblance: Esecubit Work In Progress Defunct!

Product Specification Sheet:

  • Java platform for users to develop multiple applet
  • Compatible with Java Card v3.0.4 and GP v2.2.1
  • ISO 7816, ISO 14443 and Bluetooth communication interface
  • EPD screen and low energy consumption
  • Extended API allows applet to control keypad and display

The product specification sheet also mentions that it supports the following algorithms:

  • MD5, SHA1, SHA256, SHA384, SHA512
  • DES, 3DES, TDES AES128
  • RSA1024, RSA2048, RSA4096*, ECDSA (SECP256K1, SECP256R1, SECP384), ECDH (SECP256K1, SECP256R1, SECP384)

The card is also described as having a secure element.


We could not find any documentation on how the Excel Secucard S300 specifically functions as a bitcoin wallet. Although the technical specifications for the card itself are detailed in its product specification sheet, we discovered that Excel Secu had other products that are similar iterations of the card. Excelsecu seems to be a business-to-business manufacturer with general marketing directed towards other sellers. Thus, a consumer who wants to buy a bitcoin hardware wallet would not find information such as how the private key is handled on the device. We assume that it would be another party or business which would program hardware wallet capabilities.

Our main products includes PKI Digital signature token, One-Time-Password OTP token, FIDO U2F Security Key, Smart Card, Java card, Bluetooth Card, Display Card, Bitcoin cryptocurrency hardware wallets, smart wearable devices.

What We Do Know

  • The product is marketed as a bitcoin hardware wallet albeit with sparse documentation
  • It has both input and output interfaces suitable for generating a QR code.
  • It claims to have a secure element
  • We could not find a companion app

We have no way of knowing how the private key is stored and could not find any linked publicly available source code. We also could not find tutorials or relevant reviews. Assuming that we take their word for it that the device is indeed a bitcoin hardware wallet and functions as such, and without knowledge whether the private keys are created during the manufacturing process, we can only make an educated guess for the verdict.