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.