When managing multi-chain assets in UKey Wallet, users may find that the available balance of some currencies (such as ALGO, SOL, NEAR, etc.) is less than the total balance. This phenomenon is not a limitation of the wallet plug-in, but is determined by the ledger model and resource management mechanism of the underlying blockchain protocol.
This article aims to objectively explain the reasons why different blockchains set "minimum reserved balances" or "freezing mechanisms" based on technical principles and their impact on asset operations.
Core design logic: system resources and security costs
The main purpose of setting up the balance locking mechanism in the blockchain is to maintain network performance and prevent malicious attacks:
Prevent state inflation: By requiring accounts to hold a minimum balance, it increases the cost of creating invalid/junk accounts and prevents the unlimited expansion of blockchain ledger data.
Storage Cost Alignment: On a chain that supports smart contracts, the byte space occupied by the account (such as storage asset type, contract data) needs to pay the corresponding "space rent" or pledge.
Ensure transaction security: Ensure that the account has sufficient resources to pay potential transaction fees when initiating complex interactions.
Detailed explanation of the locking mechanisms of various mainstream blockchains
1. Algorand (ALGO) — Minimum Balance Requirement (MBR)
Algorand uses Minimum Balance Requirement to ensure that the account exists on the ledger.
Base Lock: Each active account needs to reserve at least 0.1 ALGO.
Incremental Locking: Every time an account opts-in to a new asset (ASA) or associates a smart contract, the required MBR will increase.
Impact: This part of the funds is locked to support the account status and cannot be used for transfers.
2. Near Protocol (NEAR) — Storage Staking
Near introduces the concept of storage staking (often referred to as storage rent).
Logic: Users need to stake an equal proportion of $NEAR based on the physical storage space (calculated in bytes) occupied by the account data on the chain.
Release Condition: This part of the pledged $NEAR will become available again only when the user deletes data no longer needed or destroys the sub-account.
3. Solana (SOL) — Rent-Exempt
In order to maintain extremely high performance, Solana requires that accounts must hold enough $SOL to pay "rent."
Mechanism: Currently most Solana accounts achieve "Rent Forgiveness" by depositing enough $SOL to cover 2 years of rent expenses.
Current situation: In order to ensure that the account is not reclaimed by the system, this part of $SOL is actually locked in the account balance.
4. Ripple (XRP Ledger) — Foundation and Owner’s Reserve
XRP Ledger uses the Reserve mechanism to prevent the ledger from being filled with junk transactions.
Base Reserve: Creating an account requires locking a fixed amount of $XRP (currently usually 10 XRP).
Owner's Reserve: Each additional Trust Line or quote added to the account will add additional locking requirements.
Note: Unless the account is canceled (a handling fee is required for cancellation), the basic reserve cannot be transferred out.
5. Cardano (ADA) — Staking Rewards and Liquidity
Cardano's balance display is usually divided into two parts:
Available Balance: $ADA available to initiate transactions at any time.
Locked Balance (Reward): Staking earnings that have been generated but have not yet been "withdrawn" from the reward account to the payment address.
Operation: Users need to manually perform the "Claim/Withdraw" operation and transfer the reward to the available balance before sending it.
6. Bitcoin (BTC) Ordinals — UTXO Locked
Since the Ordinals protocol inscribes metadata on specific Satoshis, in order to prevent users from mistakenly consuming Satoshis containing rare engravings or NFTs as handling fees in ordinary transactions, the wallet will execute the following logic:
UTXO Isolation: Identify and "lock" UTXOs containing inscriptions.
Purpose: To ensure the traceability and integrity of digital assets and avoid the loss of inscriptions due to routine transfers.
Summary and suggestions
Blockchain | Lock type | main reason | Is it releasable? |
Algorand | MBR | Prevent ledger expansion | Partial release after asset/contract removal |
Near | Storage pledge | Pay data storage costs | Release after deleting data |
Solana | rent exemption | Keep account active | Release after closing account |
XRP | reserves | Prevent spam accounts | Most of them will be released after destroying the account. |
Bitcoin | UTXO lock | Protect Ordinals Assets | Released after transferring/selling specific inscriptions |
UKey official recommendation: When making large transfers or clearing your account, be sure to pay attention to the "Available Balance" indicator. To release locked funds, you usually need to perform corresponding reverse operations (such as removing token authorization, claiming rewards, or closing sub-accounts). UKey will continue to optimize the interface display to help you more clearly distinguish the status of each asset.