Technical Solutions for COBOL

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Redvers COBOL Signature

The Redvers COBOL Signature software package includes Digital Signature Standard (DSA) and Elliptic Curve Digital Signature Algorithm (ECDSA) capability and uses asymmetric encryption (PKI) with OAEP padding.

Main features:
  • All code is 100% pure COBOL
  • Runs on any COBOL platform
  • Supports DSA and elliptic curve (ECDSA) signatures
  • Complies with PKCS #1 v2.2: RSA Cryptography Standard
  • Supports public/private keys up to 4096 bits, in hex or Base64
  • Distributed in COBOL source code
  • Efficient, professional and fully scalable
  • Supports calls from batch or on-line (eg: CICS)
  • Free 30 day trial

DSA signatures are created and verified as specified in NIST FIPS PUB 186-4 Digital Signature Standard. ECDSA signatures conform to ANSI ANS X9.62-2005 Public Key Cryptography for the Financial Services Industry - The Elliptic Curve Digital Signature Algorithm (ECDSA). Digital signatures provide assurance of the sender's identity and confirmation that the data received has not been altered by unauthorized activity.

PKI encryption and OAEP padding logic complies with algorithms provided in the RSA Laboratories PKCS #1 v2.2: RSA Cryptography Standard. Specifically, RSAEP/RSADP are used for encryption/decryption and RSA-OAEP padding with MGF1 is used in padding and mask generation. PKI encryption uses public and private keys, according to application security requirements.

The required security level for digital signature generation/verification and PKI cryptography depends on the length of public/private keys as well as SHA-1 or SHA-2 hashing algorithms. Key sizes and hash digest lengths are specified by the calling application to ensure the correct security level is maintained.

How it Works

Redvers Consulting have been providing technical solutions to the secure transfer of confidential information for many years - see example below:

Signature Software Flowchart

The Redvers Signature Software runs standard digital signature and asymmetric encryption algorithms, so that signatures and ciphertext can be verified and decrypted by external institutions running on any computer platform.

Technical Information

The Redvers COBOL Signature 2.2 software package consists of:

  • A sample COBOL calling application program (RCSSAMP).
  • Four additional application programs to encrypt (RCSENCR), decrypt (RCSDECR), sign (RCSSIGN) and verify (RCSVERI).
  • Two Redvers Consulting subroutines (RCSCALC and RCSHASH).

All these programs should be copied to the standard source code library and compiled. RCSSAMP will need to be compiled and linked last, before starting the trial.

Redvers COBOL Signature programs can be run on EBCDIC or ASCII character encoded platforms, using big or little endian binary formats. Data exchange between subroutines uses a common communication block containing left justified, space filled parameters in hexadecimal or Base64 formats. All subroutine storage areas containing confidential information are initialized before control is returned to the calling application.

Included within the software is the Redvers calculator subroutine RCSCALC. This routine performs the modulated exponential calculations, modular inverse functions, scalar arithmetic and data conversion within the encryption/signature processes. Also included is the Redvers hashing subroutine RCSHASH, which runs SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512 algorithms. RCSCALC and RCSHASH may be used by clients for other technical application requirements without charge.

If key lengths or algorithms are required that are not currently listed in the calling parameters, please contact your account manager or use our Contact page to request an enhancement.

Download a free 30 day trial here...