Cryptography Calculators
30 free cryptography calculators in Cyber Security.
- AES Key Strength CalculatorCompare AES-128, AES-192 and AES-256 by round count, effective security bits and brute-force time, with a Grover option.
- Argon2 Memory CalculatorSize the Argon2 memory parameter in KiB blocks, validate it against the lane minimum and project peak server RAM.
- Argon2 Parallelism CalculatorChoose the Argon2 lane count for your CPU, and check the minimum memory and per-lane allocation it forces.
- Argon2 Time Cost CalculatorEstimate Argon2 hashing time from memory, passes and memory bandwidth, and get the pass count that hits your target.
- bcrypt Cost CalculatorTurn a bcrypt cost factor into hash time, server throughput and offline crack time, benchmarked against OWASP guidance.
- Certificate Chain Size CalculatorAdd up a TLS certificate chain in bytes, count the records it spans and see the handshake bandwidth it costs at scale.
- Certificate Expiry CalculatorTrack how much of a certificate's validity is spent, when renewal must start and how urgent the current state is.
- Cipher Block Size CalculatorWork out block count, padded length and the birthday-bound data limit per key for AES, 3DES and stream ciphers.
- Cryptography Health Score CalculatorScore your cryptographic estate across cipher strength, TLS version, certificate hygiene, key rotation and quantum readiness.
- CSR Size CalculatorEstimate the DER and PEM size of a certificate signing request from its key algorithm, subject and SAN count.
- Digital Signature Size CalculatorCompare signature and public-key sizes across RSA, ECDSA, Ed25519 and ML-DSA in raw, DER or Base64 encoding.
- ECC Security Level CalculatorConvert an elliptic-curve field size into security bits, the RSA modulus that matches it, and key and signature sizes.
- Encryption Overhead CalculatorBreak down the extra bytes an AEAD or CBC mode adds — nonce, padding and auth tag — and the cost across your message volume.
- Hash Collision Probability CalculatorApply the birthday bound to any digest length: collision probability at your item count and the safe volume per digest.
- HMAC Output CalculatorSize an HMAC tag, check how your key is padded or hashed, and count the compression calls a verification costs.
- Initialization Vector (IV) CalculatorGet the correct IV length and uniqueness rule for CBC, CTR, GCM or XTS, plus the random-IV collision risk at your volume.
- Key Lifetime CalculatorDerive the NIST SP 800-57 cryptoperiod for a key type, add the retention tail and check the strength holds that long.
- Key Rotation Interval CalculatorFind the rotation interval where cryptographic usage limits and your compliance policy meet, and count rotations per year.
- Nonce Length CalculatorCompare random and counter nonce strategies for AEAD: message limits, collision probability and rekey thresholds.
- PBKDF2 Iteration CalculatorPick a PBKDF2 iteration count from a target login delay, then check it against the OWASP floor and an attacker's GPU rig.
- Perfect Forward Secrecy CalculatorScore your forward-secrecy posture from the key exchange, ticket lifetime and ticket-key rotation, and size the exposure window.
- Post-Quantum Key Size CalculatorCompare FIPS 203/204 key, ciphertext and signature sizes against X25519 and Ed25519, and size the bandwidth impact.
- Quantum Security Readiness CalculatorApply Mosca's theorem to your data retention and migration timeline, and score how exposed you are to harvest-now attacks.
- Random Number Quality CalculatorRun the NIST SP 800-22 monobit frequency test on a bitstream sample and estimate its min-entropy per bit.
- Randomness Entropy CalculatorCompute Shannon entropy for a random string or passphrase from its alphabet and length, plus the offline crack time.
- RSA Key Size CalculatorMap an RSA modulus size to its NIST SP 800-57 equivalent security strength, ECC equivalent and signature size.
- SHA Hash Length CalculatorGet digest length, hex and Base64 output size, block size and collision resistance for any SHA-1, SHA-2 or SHA-3 variant.
- SSL Certificate Validity CalculatorCheck a requested certificate lifetime against CA/Browser Forum limits and see the renewal cadence it commits you to.
- TLS Handshake Time CalculatorEstimate TLS setup latency from round-trip time, protocol version and resumption mode, split into network and crypto cost.
- TLS Session Key CalculatorCount the key material a TLS 1.3 handshake derives — traffic secrets, AEAD keys and IVs — including KeyUpdate rekeys.