About

In the decentralized web (Web3), the concept of identity shifts from server-issued usernames to self-sovereign identifiers. A Decentralized Identifier (DID) acts as a cryptographically verifiable anchor, independent of centralized registries. Accuracy and entropy in generating these IDs are paramount; a predictable generator compromises the security of the entire wallet or asset chain associated with it.

This tool utilizes the browser's native crypto.getRandomValues API, which taps into the operating system's entropy pool (CSPRNG), ensuring that every ID generated is statistically unique and unpredictable. Unlike Math.random, which is deterministic and unsafe for cryptography, this generator provides the mathematical assurance required for production-grade dApps and identity systems.

Formulas

The security of a Version 4 UUID relies on the sheer size of its probability space. The identifier consists of 128 bits, where 6 bits are fixed (version/variant) and 122 bits are random.

{

N = 2¹²² ≈ 5.3 × 10³⁶Total possible combinations

The probability P of a collision after generating n identifiers is approximated by the Birthday Paradox formula:

P≈1 − e^{−n²2 × 2¹²²}

To reach a 50% chance of collision, one would need to generate approximately 2.71 × 10¹⁸ IDs, which is equivalent to generating 1 billion IDs per second for about 85 years.

Reference Data

Standard	Format Structure	Entropy (Bits)	Primary Use Case
UUID v4	8-4-4-4-12 (Hex)	122 bits	Database primary keys, trace IDs, standard referencing.
did:ethr	did:ethr:0x[40 hex chars]	160 bits	Ethereum-based identity, wallet addressing, smart contracts.
did:key	did:key:z[Base58 Encoded Key]	256 bits	Offline-first identity, ephemeral signing, secure messaging.
did:web	did:web:[domain.com]	DNS-based	Corporate identity, reputation linking to existing domains.
NanoID	[A-Za-z0-9_-]{21}	126 bits	URL-friendly unique IDs, lightweight databases.

Frequently Asked Questions

Math.random() is a Pseudo-Random Number Generator (PRNG). It is deterministic, meaning if you know the internal state or seed, you can predict future numbers. crypto.getRandomValues() is a Cryptographically Secure PRNG (CSPRNG) that uses unpredictable entropy sources (thermal noise, keystrokes, OS interrupts), making prediction mathematically infeasible.

The format is syntactically correct and cryptographically secure. However, a "real" DID often requires registration on a ledger or a specific key-pair generation process where you also hold the private key. This tool generates the public identifier. For did:key, we generate a valid public key structure, but without the private key, you cannot sign messages for this specific identity. These are best for testing, database seeding, or non-signing ID references.

Negligible. With 122 bits of entropy for UUIDs and 160+ bits for DIDs, the universe would likely succumb to heat death before you generated a duplicate on a single machine. The probability is effectively zero for any practical application.

We capture your mouse movements (X/Y coordinates) and add them to an internal entropy buffer. This user-provided randomness is mixed with the system's crypto values. While the system crypto is sufficient, this "participatory entropy" ensures that the specific moment and manner of your interaction influenced the outcome, adding a layer of physical randomness.