7 tools · hex inputs · audit logs

Cryptographic Tools

Symmetric and asymmetric encryption calculators for testing payment cryptography. AES, DES/3DES, RSA, ECDSA, and Format-Preserving Encryption (FPE) variants are all supported with hex inputs and detailed audit logs.

ISO8583StudioProfessional Payment Testing
Tool Categories
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Data Converters6 tools
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Cryptographic Tools
Encryption, decryption and security utilities
7 tools
013 tools
Symmetric ciphers
AES · DES/3DES · FPE
023 tools
Asymmetric & signatures
RSA · Thales RSA · ECDSA
031 tool
Digests
MD5 · SHA-1 · SHA-256
All tools
One calculator per algorithm family
hex-driven · audit log
AES Calculator01
Encrypt or decrypt data with AES, or compute a Key Check Value over a known key.
DES / 3DES Calculator01
Single DES or Triple DES with a wide selection of cipher modes and padding schemes commonly used by legacy payment hosts.
FPE Calculator01
Format-Preserving Encryption keeps the output in the same format as the input — e.g. encrypting a 16-digit PAN into another 16-digit numeric string.
RSA Calculator02
Six-tab tool covering the full RSA workflow from key generation through padding-aware encryption and signing.
Hash Calculator03
Generate an MD5, SHA-1 or SHA-256 digest over ASCII or hex input.
Thales RSA Calculator02
Vendor-aware RSA helpers tailored to Thales PayShield workflows.
ECDSA Calculator02
Elliptic Curve Digital Signature Algorithm with three workflow tabs.
›Opening FPE Calculator · Format-Preserving Encryption keeps the output in the same format as the input — e.g. encrypting a 16-digit PAN into another 16-digit numeric string.
Activity log
Timestamps and round-trip values on every operation.
On this page
cipher-tools · Cryptographic Tools hub — above

Introduction

The Cryptographic Tools hub — encryption, decryption and security utilities — gathers them in one place. Each calculator is dedicated to a single algorithm family and exposes the inputs typically required for payment-system testing: hex keys, hex data, IV/tweak values, and mode/padding selectors. Every operation is recorded in the activity log with timestamps and round-trip values.

AES128 / 192 / 256-bit AES with selectable cipher modes for both encryption and decryption.
DES / 3DESSingle, double, and triple DES with ECB / CBC modes and automatic padding.
RSARSA encryption, decryption, signing, and verification with custom modulus and exponents.
ECDSAElliptic Curve Digital Signature Algorithm for key generation, signing, and verification.
FPEFormat-Preserving Encryption (FF1, FF2 / VAES3, FF3, FF3-1, DFF) for tokenization use cases.
Thales RSAVendor-aware RSA helpers for Thales key blocks and LMK variant operations.

All tools

Every tool in this category — each card links to the detailed reference below.

Common UI Patterns

All cipher calculators share the same conventions:

  • Two-pane layout — Inputs on the left, an activity log on the right that records every operation with timestamps and inputs.
  • Data Input Type — Most tools have an ASCII / Hexadecimal drop-down so you can paste data either way; the field label changes based on the selection.
  • Hex keys — Keys are always entered as continuous hexadecimal (no spaces, no 0x prefix). Length is validated live.
  • Encrypt / Decrypt buttons — Pair of explicit buttons rather than an Encrypt/Decrypt toggle.
  • Copy buttons — Each output supports one-click copy to clipboard.
Tip
Use the activity log to compare consecutive runs side-by-side. The log persists until you clear it or close the tool.
01 · Symmetric ciphers

AES Calculator

Encrypt or decrypt data with AES, or compute a Key Check Value over a known key.

cipher-tools · AES Calculator — AES-128 in CBC mode with hexadecimal input — the known-answer example below, run live

Inputs

FieldDescription
AES TypeDrop-down: AES-128, AES-192, AES-256.
ModeDrop-down: ECB, CBC, CFB, OFB, KCV.
Data Input TypeDrop-down: ASCII or Hexadecimal. Changes the input field label.
Input DataMulti-line text. The field accepts ASCII or hex per the input type.
Key (Hex)32 / 48 / 64 hex chars matching the chosen AES type.
Initial Vector (IV) (Hex)Only shown for CBC, CFB, OFB. 32 hex chars.

Walk-through

  1. Pick AES Type — AES-128, AES-192, or AES-256.
  2. Pick Mode — Choose a cipher mode, or pick KCV to compute a key check value.
  3. Pick Data Input Type — ASCII or Hexadecimal.
  4. Enter Input Data — In KCV mode the input is ignored; otherwise this is the plaintext or ciphertext.
  5. Enter Key (Hex) — A hex key whose length matches the AES type.
  6. Enter IV — If the mode requires one, enter 32 hex chars in the Initial Vector (IV) (Hex) field.
  7. Click Encrypt / Decrypt — Or Calculate KCV when the mode is KCV. The result is appended to the right-hand activity log with a byte count.
KCV Mode
Selecting KCV swaps the Encrypt/Decrypt buttons for a single Calculate KCV button and hides the IV field. The output is the standard 3-byte (6-hex) check value computed over zero plaintext.

Example

AES Type:        AES-128
Mode:            CBC
Data Input Type: Hexadecimal
Key (Hex):       2B7E151628AED2A6ABF7158809CF4F3C
IV (Hex):        000102030405060708090A0B0C0D0E0F
Input Data:      6BC1BEE22E409F96E93D7E117393172A

Output:          7649ABAC8119B246CEE98E9B12E9197D
01 · Symmetric ciphers

DES / 3DES Calculator

Single DES or Triple DES with a wide selection of cipher modes and padding schemes commonly used by legacy payment hosts.

cipher-tools · DES / 3DES Calculator — DES with ECB mode, PKCS#5 padding and ASCII input

Inputs

FieldDescription
AlgorithmDrop-down: DES or 3DES.
ModeDrop-down: ECB, CBC, CFB-8, CFB-64, OFB-8, OFB-64.
PaddingDrop-down: None, Zeros, Spaces, ANSI X9.23, ISO 10126, PKCS#5, PKCS#7, ISO 7816-4, Rijndael, ISO 9797-1 Method 1, ISO 9797-1 Method 2.
Data Input TypeDrop-down: ASCII or Hexadecimal. The input data field label updates accordingly (Input Data (ASCII) / Input Data (Hex)).
Input DataMulti-line text.
Key (Hex)16 hex (DES), 32 hex (2-key 3DES) or 48 hex (3-key 3DES).
Initialization Vector (IV)16 hex chars (8 bytes). Shown for non-ECB modes; a KCV chip displayed alongside.

Walk-through

  1. Pick Algorithm — DES for single DES, 3DES for double or triple length keys.
  2. Pick Mode — ECB or CBC for the typical case; CFB-8/CFB-64/OFB-8/OFB-64 for streaming variants.
  3. Pick Padding — Pick the scheme expected by your host. ISO 9797-1 Method 1 or Method 2 are common in payments.
  4. Pick Data Input Type — ASCII or Hexadecimal.
  5. Enter Input Data in the matching format.
  6. Enter Key (Hex) — The variant (DES, 2-key 3DES, 3-key 3DES) is inferred from the key length you provide.
  7. Enter IV if a chaining mode is selected.
  8. Click Encrypt / Decrypt — The result card displays the output in HEX, plus an ASCII view if the bytes are printable, with copy / clear actions.

Use Cases

  • Encrypting / decrypting PIN blocks under a working key (TPK / PEK).
  • Generating 3DES MACs by chaining ECB operations.
  • Verifying ZPK / ZMK translations during HSM integration.
01 · Symmetric ciphers

FPE Calculator

Format-Preserving Encryption keeps the output in the same format as the input — e.g. encrypting a 16-digit PAN into another 16-digit numeric string. Useful for tokenisation and PCI-scope reduction.

cipher-tools · FPE Calculator — FPE-FF1 with radix 10, AES-128, a hexadecimal key, the Use Tweak option on and the tweak field

cipher-tools · FPE Calculator — FPE-FF2 (VAES3) with separate Radix and Tweak Radix selectors

Tabs (5)

Each tab is a self-contained calculator for the named variant:

  • FPE-FF1
  • FPE-FF2 (VAES3)
  • FPE-FF3
  • FPE-FF3-1
  • FPE-DFF[OFF-2]

Inputs (per tab)

FieldDescription
RadixDrop-down: 10 (digits), 26 (lower-case alpha), 36 (alphanumeric).
Tweak RadixDrop-down. Only shown for FPE-FF2 and FPE-DFF.
Encryption TypeDrop-down: AES-128, AES-192, AES-256.
Key Input TypeDrop-down: ASCII or Hexadecimal.
KeyLength matches the encryption type and input format.
Use Tweak?Checkbox — only on FPE-FF1. When on, an animated Tweak field appears.
TweakVisible when applicable; format depends on the variant.
DataMulti-line input matching the chosen radix alphabet.

Walk-through

  1. Pick the FPE tab matching your spec — FPE-FF1 or FPE-FF3-1 for new work.
  2. Pick Radix — 10 for numeric tokens such as PANs.
  3. Pick Encryption Type — the AES variant for the underlying block cipher.
  4. Pick Key Input Type and enter the Key.
  5. (FF1 only) tick Use Tweak? if you have one, then enter it.
  6. Enter Data — The string must contain only characters in the radix alphabet.
  7. Click Encrypt or Decrypt — The output preserves the original length and alphabet.

Example: Tokenize a PAN (FPE-FF1)

Radix:           10
Encryption Type: AES-128
Key Input Type:  Hexadecimal
Key:             2B7E151628AED2A6ABF7158809CF4F3C
Use Tweak?:      on
Tweak:           39383736353433323130
Data:            0123456789012345

Output:          9095444784296454
02 · Asymmetric & signatures

RSA Calculator

Six-tab tool covering the full RSA workflow from key generation through padding-aware encryption and signing.

cipher-tools · RSA Calculator — The Keys tab with a 2048-bit key length above the Modulus, Public Exponent and Private Exponent fields

Tabs (6)

  • Keys — Generate or paste a key pair.
  • Encrypt — Encrypt with PKCS1 or no padding.
  • Decrypt — Decrypt ciphertext with the corresponding key.
  • Sign — Produce a signature over a message or hash.
  • Verify — Verify a signature against a hash.
  • OAEP — Encode / decode with OAEP padding.

Keys Tab

  • Key Length (bits) — 1024, 2048, 3072, 4096.
  • Generate Keys button.
  • Modulus, Public Exponent (e), Private Exponent (d) — All hex; you can also paste pre-existing components instead of generating.

Encrypt Tab

  • Encoding Method — Public (encrypt with public key) or Private.
  • Padding — PKCS1 or No Padding.
  • Input Data Format — ASCII or Hex.
  • Data to Encrypt.
  • Button: Encrypt.

Decrypt Tab

  • Decoding Method — Private or Public.
  • Padding — PKCS1 or No Padding.
  • Data to Decrypt (Hex).
  • Button: Decrypt.

Sign / Verify Tabs

  • Sign — Input Data Format (ASCII / Hex) and Data to Sign; click Sign.
  • Verify — Hash (Hex) and Signature (Hex); click Verify.

OAEP Tab

  • Method — Encode or Decode.
  • Hash Function — SHA-1, SHA-224, SHA-256, SHA-384, SHA-512.
  • Result Length (bits) — 1024, 2048, 4096.
  • Data (Hex), Encoding Parameters (Label, Hex).
  • Button label changes between Encode and Decode based on the selected method.
02 · Asymmetric & signatures

Thales RSA Calculator

Vendor-aware RSA helpers tailored to Thales PayShield workflows.

cipher-tools · Thales RSA Calculator — The Generate tab: private exponent, primes, exponents and coefficient with a 2048-bit key length

Tabs (3)

Generate

Construct an RSA key pair from CRT components (or generate a fresh one). Inputs:

  • Private Exp. (d)
  • Prime 1 (p)
  • Prime 2 (q)
  • Exponent 1 (dModP1)
  • Exponent 2 (dModQ1)
  • Coefficient (iqmp)
  • Key Length (1-4096)

Buttons: Generate (d) from Components, Generate New Random Key.

cipher-tools · Thales RSA Calculator — Thales Key Block: DES and AES KBPK fields, public and private key headers, AES key block encryption and Wrap / Unwrap

Thales Key Block

Wrap or unwrap a key pair under a Key Block Protection Key. Inputs:

  • DES KBPK, AES KBPK
  • Public Key Header, Private Key Header
  • Key Block Encryption — AES or DES.
  • Input Format — ASCII or Hex.
  • Public Key, Private Key

Buttons: Wrap Key Block, Unwrap Key Block.

Thales LMK Variant

Apply Thales LMK variants. Inputs:

  • LMK Pair 34-35
  • LMK Pair 36-37
  • Authentication Data
  • Modulus Encoding — DEC / DER variants.
  • Public Key, Private Key

Button: Process LMK Variant.

02 · Asymmetric & signatures

ECDSA Calculator

Elliptic Curve Digital Signature Algorithm with three workflow tabs.

cipher-tools · ECDSA Key Management — ECDSA Key Management on the Keys tab with NIST P-256 selected and the uncompressed public key form

Keys Tab

  • ECC Curve Name — NIST P-256, NIST P-384, NIST P-521, plus the Brainpool curve variants.
  • Private Key (Hex).
  • Public Key (Hex).
  • Public Key Form — Uncompressed or Compressed.

Buttons: Generate New Public Key, Is Point on Curve?, Generate Random Key Pair, Validate Current Key Pair.

Sign Tab

  • Hash Type — SHA-1, SHA-256, SHA-384, SHA-512.
  • Input Data Format — ASCII or Hex.
  • Data to Sign.

Button: Sign Data. Output is the (r, s) pair in hex.

Verify Tab

  • Hash (Hex).
  • Signature (Hex).

Button: Verify Signature.

Cipher Modes Reference

Mode availability depends on the calculator. AES exposes ECB / CBC / CFB / OFB / KCV. DES / 3DES exposes ECB, CBC, and the CFB-8 / CFB-64 / OFB-8 / OFB-64 byte/feedback variants.

ModeIV?Properties
ECBNoEach block independent. Simple but leaks plaintext patterns.
CBCYesEach block XOR-chained with the previous ciphertext. Secure with unique IV.
CFB / CFB-8 / CFB-64YesSelf-synchronising stream mode. The numeric variants set the feedback width in bits.
OFB / OFB-8 / OFB-64YesKey-stream mode independent of plaintext.
KCVNoAES-only. Computes the standard 3-byte Key Check Value over zero plaintext.
03 · Digests

Hash Calculator

Generate a message digest over arbitrary input. Useful for checking a known-answer test vector, or for producing the hash an RSA or ECDSA Verify step expects as its input.

cipher-tools · Hash Calculator — ASCII input, SHA-256 selected, the text Hello, World! in the input field

Inputs

FieldDescription
Data Input TypeDrop-down: ASCII or Hexadecimal. Choose Hexadecimal when hashing raw bytes such as a key or a block of card data.
Hash TypeDrop-down: MD5, SHA-1, SHA-256.
Input DataThe message to digest, in the format chosen above.

Walk-through

  1. Pick Data Input Type — ASCII for text, Hexadecimal for raw bytes.
  2. Pick Hash Type.
  3. Enter Input Data.
  4. Click Calculate Hash. The digest is written to the activity log alongside the input, so a run can be compared against a published vector.
Note
MD5 and SHA-1 are here because payment protocols and test packs still reference them. Neither is collision-resistant — use them to reproduce an existing vector, not to secure new data.

Padding Schemes (DES / 3DES)

The DES / 3DES calculator exposes the full set of padding schemes used across legacy and modern payment protocols. Pick the one your host expects:

SchemeNotes
NoneInput must be an exact multiple of 8 bytes.
ZerosPads with 00 bytes. Cannot recover trailing zero bytes.
SpacesPads with ASCII space (0x20).
ANSI X9.23Random bytes followed by a length byte.
ISO 10126Random bytes followed by a length byte (similar to X9.23).
PKCS#5 / PKCS#7Self-describing: pad bytes equal the pad length.
ISO 7816-4Single 0x80 followed by zero bytes.
RijndaelVariant used in the original Rijndael spec.
ISO 9797-1 Method 1Zero-pad to next block boundary (no length signal).
ISO 9797-1 Method 2Single 0x80 then zeros — recommended for MAC inputs.

Tips

  1. Use the Bitmap Calculator under Tools → Payment Utilities to inspect block alignment when sizes look odd.
  2. For HSM-bound keys, prefer Thales RSA → Thales Key Block over the raw RSA tool to keep wrapping consistent.
  3. If a known answer test fails, double-check the IV is in hex (not ASCII) and the data length matches the mode requirements.

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