Cryptographic Key Exchange Using Blockchain Technology


  • University of Thi-Qar, College of Education for Pure Science, Computer Science, Iraq
  • University of Thi-Qar, College of Education for Pure Science, Computer Science, Iraq


Cryptographic key management systems (KMS) are an important component of secure communications
systems and organisations must protect sensitive information by maintaining confidentiality, integrity,
and reliability. In this paper, we create an efficient cryptographic key management application that uses
blockchain technology (BC) and fingerprint biometrics to meet this demand. A private network of ten
authorised users is created according to the Fingerprint Verification Competition 2000 (FVC2000)
database. They create and exchange encrypted keys according to security standards that include
confidentiality, authenticity, trust, and limited access to the system. The system requires each authorized
user to log in using their email and password, in addition to their fingerprint.
The fingerprint is converted to binary if it is grayscale. If the fingerprint already exists in binary format, the system will extract the fingerprint features in matrix form by processing any missing or incorrect
information with an emphasis on accurate representation. A 256-bit encrypted key is produced from this
matrix after feature retrieval, by converting the feature matrix into a long string which is then fed through
the secure hash algorithm 256 (SHA256) function. The app uses blockchain technology to encrypt the
key, apply additional encryption, and associate it with a unique hash. The encrypted key is contained within a block. Users then securely exchange this encrypted block. The application strictly accepts
authorised users and rejects unauthorised users. The encryption KMS application provides a high level of
security and reliability for organizations looking to protect their encryption keys by combining the use of
fingerprint biometrics and BC technology.


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